A Stereological Study of the Different Cell Populations in Chicken Testes Treated with Follicle-Stimulating Hormone during Embryonic Development

Quantitative morphological methods were used to analyse the histomorphometric changes and variations in the number and size of cells from diverse cellular populations in testes of newly hatched chicks treated with follicle stimulating hormone (FSH) during embryonic development. The tissue was fixed and embedded in Epon and sections were morphometrically measured under light microscopy, using point counting for volume densities and the Floderus equation to determine numerical density. The average volume of the individual cell was determined by dividing the volume density by the numerical density. Results indicate that FSH administration causes an increase in the number of Sertoli cells and spermatogonia, as well as enlargement of the individual Sertoli cells leading consequently to an increase in the diameter and volume density of the testicular seminiferous tubules. Results also reveal an increase in the volume density of the interstitial cords of the Leydig cells, this expansion is due to the enlargement of the individual Leydig cells and not to an increase in their number, which remains constant. We conclude that testes of chick embryos are able to respond to FSH treatment, as revealed by the changes in the number and size of the cells conforming the diverse cellular populations of the testis. FSH treatment during embryonic development induces histomorphometric changes in both the interstitial tissue and seminiferous tubules, accelerating their growth and differentiation.     

Effect of luteinising-hormone in vivo on ovarian cell subpopulations of newly-hatched chicks

1. We analysed the number and size of different ovarian cell subpopulations of newly-hatched chicks by ovarian cell suspension count and morphometric/stereological methods as well as delta5-3beta-hydroxysteroid dehydrogenase (delta5-3beta HSD) activity in these cells treated in vivo with LH during embryonic development. 2. Fertile White Leghorn eggs received 1 microg LH applied to the chorioallantoic membrane on days 13, 15, and 17 of incubation. All animals were killed within 24 h after hatching, the left ovary was dissected and processed. 3. The results indicate that the number of germ, pregranulosa, interstitial and undifferentiated cells was not affected by LH treatment. However, we observed an increase in the size of individual interstitial cells of the ovarian medulla. In these cells, delta5-3beta HSD activity was increased in response to LH. 4. These findings suggest that LH does not exert a proliferative effect on the cells of the prefollicular ovary of the chick and that interstitial cells can be target cells for LH, increasing their steroidogenic activity due to LH treatment.     

Prenatal and neonatal exposure to flutamide affects function of Leydig cells in adult boar

In this study, flutamide, an androgen receptor antagonist, was used as a tool to better understand the role of androgen receptor signaling and androgen signaling disruption during fetal and neonatal periods on porcine Leydig cell development and function. Flutamide, 50 mg kg(-1) d(-1) was administered into pregnant gilts during gestational days 20 to 28 and days 80 to 88 and into male piglets on postnatal days 2 to 10 (PD2). Leydig cells of flutamide-exposed boars, especially those of PD2 males, displayed morphologic alterations, increased size, and occupied increased area (P < 0.001) of the testes when compared with the control. Despite this, testosterone concentrations were reduced significantly in comparison with those of controls (P < 0.05, P < 0.001). Reduced testosterone production in response to flutamide exposure appeared to be related to changes in testosterone metabolism, as shown by increased aromatase mRNA (P < 0.05, P < 0.01), protein expression (P < 0.01, P < 0.001), and elevated estradiol concentrations (P < 0.001). Moreover, impaired Leydig cell responsiveness to LH was indicated by the decreased expression of LH receptor (P < 0.05, P < 0.001). No significant effect of flutamide was found on LH and FSH concentrations. Taken together, our data indicate that flutamide when administered during prenatal or neonatal period have a long-term effect on Leydig cell structure and function, leading to androgen-estrogen imbalance. Leydig cell failure was most evident in adult boars neonatally exposed to flutamide, suggesting that androgen action during neonatal development is of pivotal importance for the differentiation and function of porcine adult Leydig cell population.     

Further evidence for the involvement of anatomical parameters of the cardiopulmonary system in the development of ascites syndrome in broiler chickens

Eggs from a broiler line were incubated at two different altitudes and hatched. Relative heart and lung weights, volumes of the heart, lung and thoracic cavity, incidence of right ventricular hypertrophy and ascites, and related physiological parameters were followed in the day-old chickens hatched from the above eggs. Lung and heart weights as a percentage of body weight, lung and heart volumes relative to the volume of the thoracic cavity after removing the heart and lungs were higher in chickens hatched at high altitude. Additionally, embryonic triiodothyronine (T3) and thyroxine (T4) levels relative to cardiopulmonary parameters were higher in day-old chickens that hatched at high altitude as compared with chickens hatched at low altitude. This was associated with a lower incidence of right ventricular hypertrophy and ascites in chickens hatched at high altitude. Our data indicate that chronic hypoxia interacting with the endogenous functions of embryos during embryonic development at high altitude, as adaptation mechanisms, changed the developmental trajectories of cardiopulmonary parameters in postnatal chickens. This important development facilitates an increase in the gas exchange area in broiler chickens, thus lowering their susceptibility to pulmonary hypertension and ascites.     

Effects of Oxytropis glabra DC Poisoning on the Reproductive Organs in Hetian Sheep Ewes

The study was aimed to research the effects of Oxytropis glabra DC (O.glabra DC) poisoning on reproductive organs coefficent, reproductive performance and related gene expression in Hetian sheep ewes. The sera, hypothalamus, pituitary and ovary of Hetian sheep ewes cases poisoning of O. glabra DC were collected, the organ exponent and contents of GnRH, FSH, LH, E₂ and P₄ in serum were measured, then the mRNA expression of reproductive genes were measured. The result demonstrated that the index of hypothalamus, pituitary and ovary were extremely significantly higher than normal sheep (P < 0.01),the follicle number on the surface of the ovaries in poisoning groups were significantly lower than normal sheep (P < 0.05). The result of hematoxylin-eosin staining showed that the nuclear of neuronal cells in hypothalamus were pyknosis and hyperchromatic; The nuclear of cells in pituitary deformation and hyperchromatic, cytoplasm decreased; The primary oocyte in ovary dissolved, disappeared, interstitial blood vessel expanded. The content of GnRH, FSH, LH, E₂ and P₄ in serum in poisoned Hetian sheep ewes were extremely significantly lower than normal sheep (P < 0.01). The mRNA expression levels of Kiss-1, GPR54, ERα in hypothalamus, GnRHR in pituitary and FSHR and LHR in ovary were extremely significantly lower than normal sheep (P < 0.01). The result showed that O. glabra DC poisoning could affect Hetian sheep ewes reproductive system by affecting microstructure and ultrastructure of hypothalamus-pituitary-ovarian axis.     

Surgical denervation of porcine ovaries during the middle luteal phase of the oestrous cycle changes their morphology and steroidogenic activity

Changes in both the morphology and the steroidogenic activity of porcine ovaries denervated surgically on day 12 of the oestrous cycle were studied. Neurectomy of the plexus and the superior ovarian nerves caused a dramatic reduction in the number (or even a disappearance) of dopamine-beta-hydroxylase- and/or neuropeptide tyrosine-immunoreactive nerve terminals. On day 20 of the subsequent oestrous cycle, the number of small follicles increased (P < 0.01) and that of large follicles decreased (P < 0.05) in the denervated ovaries, as compared to the controls. Neurectomy led to a decrease in the level of progesterone (P4; P < 0.001) and androstenedione (A4; P < 0.01) in the fluid from small follicles, A4 (P < 0.001) and testosterone (T; P < 0.05) in the fluid from medium-sized follicles, as well as in the content of all these steroids in the fluid from large-sized follicles (P < 0.001 for P4 and P < 0.05 for A4 and T). Denervation also caused a decrease in the content of A4 (P < 0.01) and T (P < 0.001) in the wall of follicles. Neurectomy resulted in a significant increase in the immunoexpression of cholesterol side-chain cleavage cytochrome P450 in the follicles and a decrease of 33-hydroxysteroid dehydrogenase. After denervation, plasma levels of LH, P4, A4, T, oestrone and oestradiol-17beta were lower (P < 0.05-0.001) on the particular days of the study than in the control group. Our data revealed that the denervation of ovaries during the middle luteal phase of the oestrous cycle in gilts caused distinct changes in both the morphology and the steroidogenic activity of the organ, confirming an important role of the peripheral nervous system in the control of the gonad in this species.     

Study on the Changes of Reproductive Hormone and Regulation of Follicle Development During the Reproductive Cycle of Yili Goose in Xinjiang

This experiment was aimed to study the changes of reproductive hormone and regulation of follicle development during the reproductive cycle of Yili goose in Xinjiang. 2 years old Yili goose were chosen which were in good health and similar weight. 32 samples were randomly selected to take blood samples for hormone detection during the laying, broodiness and ceased periods, and 15 samples were randomly selected to gather ovarian tissue for the observation of the development of ovary and follicular. The results showed that during the laying period, the GnRH of the Yili goose was extremely significantly higher than the broodiness and ceased periods of 16.78% and 58.29% (P<0.01);PRL was significantly lower than the broodiness period of 13.00% (P<0.05), and was extremely significantly higher than the ceased period of 28.94% (P<0.01); FSH was higher than the broodiness period of 6.98% (P>0.05),and was extremely significantly higher than the ceased period of 21.12% (P<0.01); LH was extremely significantly lower than the broodiness period of 8.38% (P<0.01),and was extremely significantly higher than the ceased period of 16.84% (P<0.01); E₂ were extremely significantly higher than that the broodiness and ceased periods of 29.80% and 112.40% (P<0.01); P₄ levels were extremely significantly higher than the broodiness and ceased periods of 28.89% and 30.34% (P<0.01). The ovary volume and weight of Yili goose were extremely significantly higher than that of broodiness and ceased periods (P<0.01). In the laying period, the mature follicles of Yili goose were significantly larger than that of the broodiness and resting periods, the number of secondary follicles was more and the number of primary follicles was lesser. Ovarian growth and mature follicle atresia, granule layer shrinkage, inward depression, cytoplasmic cavity, follicular atrophy at all levels in the broodiness period. The follicle cytoplasmic cavity of the ovary was larger in the ceased period than broodiness period, and inward concave further deeper, a large number of primordial follicles evenly arranged. Thus, during the laying period, the responses of GnRH, E₂ and LH of Yili goose were active and played a leading role on the development of ovarian and follicular. PRL and LH maintained a high level of secretion, cooperated to maintain the broodiness behavior during the broodiness period.     

小花棘豆中毒对和田羊母羊繁殖器官的影响

试验旨在探讨小花棘豆（Oxytropis glabra DC）中毒对和田羊母羊繁殖器官指数、性激素水平和相关基因mRNA表达量的影响。以小花棘豆中毒和田羊母羊为研究对象,采集血清后屠宰,采集试验羊的丘脑、垂体和卵巢组织,测定其脏器系数,检测血清中促性腺激素释放激素（GnRH）、促卵泡素（FSH）、促黄体素（LH）、雌二醇（E₂）和孕酮（P₄）含量的变化,并检测各组织中相关繁殖基因的表达。结果显示,小花棘豆中毒和田羊母羊丘脑、垂体和卵巢指数均极显著升高（P < 0.01）,且卵巢表面卵泡数显著下降（P < 0.05）,HE染色表明丘脑神经元细胞固缩、浓染;垂体中细胞核变形、浓染,胞浆减少;卵巢中初级卵母细胞溶解、消失,间质血管扩张。小花棘豆中毒和田羊母羊血清中GnRH、FSH、LH、E₂和P₄含量均极显著下降（P < 0.01）,丘脑中Kiss-1、GPR54、ERα mRNA,垂体中GnRHR mRNA和卵巢中FSHR、LHR mRNA表达量均极显著下降（P < 0.01）。结果表明,小花棘豆毒性成分可通过丘脑-垂体-性腺轴影响和田羊母羊的生殖系统。     

Effects of latex from "Amapazeiro"Parahancornia amapa (Apocynaceae) on blowfly Chrysomya megacephala (Diptera: Calliphoridae) post-embryonic development

Nowadays, insect control is usually carried out using chemical insecticides, but insect resistance and other negative side effects have prompted the search for alternatives. Biopesticides provide a positive alternative to synthetic pesticides because they have low impact on the environmental, low toxicity to humans and low costs among other advantages. This research was carried out to evaluate the activity of Parahancornia amapa (Huber) Ducke (Apocynaceae) lyophilized latex on the post embryonic development of Chrysomya megacephala (F.) (Diptera: Calliphoridae). Larvae treated with 1.0% latex showed a shorter post embryonic development period (larval, pupal and newly hatched larvae to adult); whereas larvae treated with 3.0% latex provoked a prolongation of these periods. Viability (53%) was also very low at the newly hatched larvae to adult period for larvae treated with 3.0% latex, indicating that latex from P. amapa at high concentrations could change C. megacephala post embryonic development.     

Embryonic and larval development of garpike from the Adriatic Sea

Although information about embryonic and larval development of garpike, Belone belone (Linnaeus, 1761), is present in the published literature, the bulk of research concerns garpike from the northeastern Atlantic Ocean and the Baltic Sea. The present work describes the embryonic and larval development of garpike, Belone belone, from the Adriatic Sea, and methods used for incubation of fertilized eggs in aquarium conditions. Because garpike is, as suggested by some authors, divided into subspecies, we conclude that some differences in embryonic development could also be expected. In the present study, eggs were fertilized using the dry fertilization method and were incubated in a tank equipped with aeration and constant sea water flow. Salinity and content of dissolved oxygen were constant, and the temperature varied between 19.4 and 22.3°C. Eggs were spherical, measuring 3071.9 ± 75.73 μm in diameter. Yolk sacs were homogeneous and did not contain oil globules. The first larvae hatched 329 h and 47 min after fertilization. Absorption of the yolk sac occurred 17 h – 48 h after hatching and the total length of newly hatched larvae was 9.78 mm. The peculiarities observed in the embryonic and early larval development are evidence of an exceptional plasticity and adaptive potential, which could be considered as helpful features in extending the natural range of occurrence of this species.     

Ovarian activity,transuterine embryo migration and prenatal losses in Ethiopian highland ewes

A study was conducted on 1442 Ethiopian highland ewes to determine the seasonality of ovarian activity, intrauterine embryo migration and prenatal reproductive wastage. Assessment of ovarian follicular activity revealed that a higher (p < 0.01) proportion of ewes ovulated in the dry season than in the heavy and light rainy seasons. However, there was a tendency (p = 0.057) of decline in the mean number of ovulations per ewes during the light rains. The mean diameter of the largest follicle on the ipsilateral ovary was higher (p < 0.01) in both ewes with single and those with twin corpora lutea (CL) than on the contralateral ovary; and, compared to ewes with single CL, it was higher (p < 0.05) in those with twin CL. The right ovary was more active (p < 0.001) only in single-ovulating ewes. Similarly, a higher (p < 0.001) proportion of ewes were pregnant in the right horn. Embryos migrated to the opposite horn in single-, twin- and triple-ovulating ewes. There was a higher (p < 0.001) tendency for the left-to-right migration than the opposite. There was significant (p < 0.01) association between embryo loss and site and number of ovulations. Embryo loss was higher (p < 0.01) in ewes with twin ovulations on the right ovary. It is very likely that these results indicate a better chance of embryo survival in the right uterine horn.     

Expression of nerve growth factor (NGF), and its receptors trkA and p75 in ovaries of the cyclic golden hamster (Mesocricetus auratus) and the regulation of their production by luteinizing hormone

In the present study, changes in localization of nerve growth factor (NGF) and its receptors, trkA and p75 in the ovary were investigated during the estrous cycle of the golden hamster. The effect of LH surge on changes in localization of NGF, trkA and p75 in the ovary was also investigated. NGF and its receptors trkA and p75 were localized in oocytes, granulosa cells and theca cells of various stages of follicles throughout the estrous cycle. NGF and its two receptors were also present in numerous interstitial cells and luteal cells. The number of interstitial cells staining positively for NGF and its two receptors was greater in ovaries of day 1 (day 1=day of ovulation) than the other days during the estrous cycle. Treatment with the antiserum against luteinizing hormone releasing hormone (LHRH-AS) at 1100 h on day 4 completely blocked ovulation. There were few positive reactions for NGF and its two receptors in interstitial cells 24 hr after LHRH-AS injection. The effect of LHRH-AS treatment was blocked by a single injection of 10 IU human chorionic gonadotropin. The distinct widespread distribution of NGF and its two receptors in the ovary of golden hamsters suggest that NGF may be an important growth factor for regulation of ovarian function. Furthermore, the LH surge may be an important factor for inducing production of NGF and its two receptors in interstitial cells of the cyclic golden hamster.     

Total lipid and triacylglycerol contents in the liver of broiler and layer chickens at embryonic stages and hatching

To compare the hepatic function of broiler and layer chickens (Gallus gallus domesticus) at various embryonic stages and hatching, the total lipid and triacylglycerol (TG) content were determined. The chicken embryos accumulated a large amount of lipids in the liver and the total lipid content gradually increased toward hatching, though no significant difference was observed between broilers and layers. The TG contents in the liver increased considerably with developmental stage. At embryonic day 14 the TG content in the liver was similar between broilers and layers; thereafter, it was 1.3 and 2.2 times higher in broilers than in layers at embryonic day 18 and for newly hatched chicks, respectively. Chick embryos accumulate an excessive amount of cholesterol ester in the liver, but cholesterol ester is replaced by TG after hatching. The results of hepatic TG contents in the present study suggest that the development of the hepatic function between broilers and layers may already differ at embryonic stages.     

催青温度对家蚕二化性品种丙酮酸脱氢酶激酶基因(BmPDK)表达的影响

丙酮酸脱氢酶激酶(PDK)在生物体的新陈代谢中具有重要的生理功能。为了探讨家蚕(Bombyx mori)PDK基因的表达特性,用蛾区半分法将二化性家蚕品种的活化越年卵(丙2期)分别以常温(25℃)光照和低温(15℃)黑暗催青,通过实时荧光定量PCR技术检测分析2种温度催青处理后家蚕不同发育阶段和不同组织的BmPDK表达水平。常温光照催青区BmP-DK的表达水平表现出发育时期和组织差异:胚胎发育阶段BmPDK在己4期的表达水平最高,其次是戊2、己3和己5期;幼虫发育阶段BmPDK的表达水平在蚁蚕期极显著高于其它龄期,5龄期在卵巢和精巢的表达水平高于其它组织;蛹期BmPDK的表达水平比其它发育时期低;成虫期的表达水平与胚胎发育末期相当,其中雌蛾的脂肪体和卵巢中BmPDK的表达水平较高。推测BmPDK在家蚕胚胎发育末期及产卵过程中有重要作用。催青温度影响BmPDK在家蚕各发育时期及卵巢组织中的表达水平:胚胎发育阶段戊2期BmPDK的表达水平为常温催青区显著高于低温催青区,己3～己5期常温催青区BmPDK的表达呈低-高-低的趋势,而低温催青区则呈上升趋势;蚁蚕期BmPDK表达水平为低温催青区极显著低于常温催青区;蛹期和成虫期卵巢中,常温催青区BmPDK的表达水平极显著高于低温催青区。催青温度对二化性家蚕BmPDK的表达的影响主要出现在胚胎戊2期、胚胎己3期～蚁蚕期、蛹期、成虫期。     

Endocrine and cellular characteristics of corpora lutea from cows with a delayed post-ovulatory progesterone rise

The timing of the post-ovulatory progesterone rise is critical to the embryonic development and survival. The aim of this study was to determine the underlying causes of delayed post-ovulatory progesterone rises. Two groups of non-lactating dairy cows with early (n = 11) or late (n = 9) post-ovulatory progesterone rises were created by inducing luteolysis in the presence of either a large (> 10 mm) or small (< 10 mm) follicle, respectively. LH pulses were measured on days 4 (all cows) and 7 (n = 7, early; n = 5, late) (day 1= ovulation). The cows were slaughtered on day 5 (n = 4 each group) or 8 (n = 7, early; n = 5, late). Immunohistochemical analysis for endothelial cells (von Willebrand Factor, VWF), steroidogenic cells (3beta-HSD) and proliferation marker (Ki67) were performed. The basal progesterone production and LH responsiveness (0.001-100 ng/ml) of dispersed luteal cells was investigated. The luteal concentrations of FGF-2 and VEGF were measured by ELISA and RIA, respectively. There were no differences in LH pulse characteristics, area of VWF staining, proliferation index, steroidogenic cell characteristics, basal or LH-stimulated progesterone production by luteal cells between cows with an early or late progesterone rise (P > 0.10). However, the area of VWF staining increased from days 5 to 8, while the proliferation index decreased (P < 0.05). Furthermore, the luteal cells were more responsive to LH on day 8 (P < 0.01). Luteal concentrations of FGF-2 were higher on day 5 (P = 0.05), while VEGF was greater on day 8 (P < 0.01). In conclusion, we have clearly shown that LH support, degree of vascularization or luteal cell steroidogenic capacity were not the major factors responsible for inadequate secretion of progesterone by the developing bovine CL.     

Prenatal and neonatal exposure to the antiandrogen flutamide alters connexin 43 gene expression in adult porcine ovary

Connexin 43 (Cx43) is the predominant gap junction protein within porcine ovary and is required for proper follicle and corpus luteum (CL) development. Recent research suggests maternally or neonatally mediated effects of antiandrogens on reproductive function during adulthood, notably those dependent on gap junctional communication. The current study was conducted to determine whether late gestational or neonatal exposure to the antiandrogen flutamide influences Cx43 gene expression in the adult porcine ovary. Flutamide was injected into pregnant gilts between days 80 and 88 of gestation and into female piglets between days 2 and 10 posnatally. After animals reached sexual maturity, the ovaries were collected from treated and nontreated (control) pigs. Expression of Cx43 mRNA and protein was determined for preantral and antral follicles and for CLs. In addition, 3β-hydroxysteroid dehydrogenase (3β-HSD) expression and progesterone concentration were determined for luteal tissues. In preantral follicles, Cx43 mRNA was down-regulated (P < 0.01) following maternal and neonatal flutamide exposure. In large antral follicles, Cx43 mRNA was up-regulated (P < 0.01) after neonatal flutamide administration. Immunofluorescence showed that Cx43 expression decreased (P < 0.001) in preantral follicles and increased (P < 0.001) in large antral follicles following flutamide exposure. In luteal tissues, Cx43 and 3β-HSD expression and progesterone concentration decreased (P < 0.01) after postnatal flutamide treatment. Overall, these results suggest the involvement of androgens in the regulation of Cx43 expression in pig ovary. Moreover, alteration of Cx43 expression by the administration of flutamide during particular prenatal and neonatal time periods may affect porcine follicle development, as well as CL formation and function.     

Maternal treatment with somatotropin alters embryonic development and early postnatal growth of pigs

A possible management strategy to alter fetal development and enhance sow productivity and progeny performance was examined by maternal administration of porcine somatotropin during early gestation. Eighteen crossbred gilts were bred naturally to boars of similar genetics, and pregnancy was confirmed between Days 21 and 24 of gestation by ultrasound. All animals were allowed ad libitum consumption of a 16% CP gestation diet through Day 21 of gestation and 3.0 kg/d for the remainder of gestation. Gilts were injected twice daily with 0 (n = 10) or 15 μg/kg body weight (BW) (n = 10; total, 30 μg/kg BW per d) pituitary-derived porcine somatotropin (pST) during Days 28 to 40 of gestation. Data were collected postmortem during embryonic, neonatal, and market-weight phases. At 41 d of gestation, pST treatment increased embryonic survival (87.9 versus 77.0%; P < 0.05) and embryo crown rump lengths (77.96 versus 65.14 mm; P < 0.01), but embryo weight was not altered (10.15 and 9.03 g; P > 0.10). Pigs from pST-treated gilts had increased (P < 0.01) crown rump lengths at birth (31.5 versus 30.4 cm) and 21 d (50.9 versus 48.4 cm). However, no differences were observed in birth or 21-d weights as a result of pST treatment (P > 0.10). Neonatal carcasses of progeny (20 kg BW) from the pST-treated gilts had heavier semitendinosus muscles (76.1 versus 66.0 g; P < 0.10), larger longissimus muscle cross-sectional area (10.1 versus 8.2 cm²; P < 0.05), longer sides (51.2 versus 47.9 cm; P < 0.001), and decreased 10th rib backfat (6.67 versus 8.64 mm; P < 0.001) compared with those of controls. Carcasses of market-weight progeny (100 kg BW) from pST-treated gilts had larger longissimus muscle cross-sectional area (P < 0.10), heavier trimmed loins (P < 0.10), and longer carcass sides (P < 0.05). Data are supportive of a hypothesis that mechanisms during early embryonic development are sensitive to manipulation through selected management strategies of the sow and that modifications of this strategy may serve as a model for the examination of molecular and cellular events controlling early embryonic growth.     

新疆伊犁鹅繁殖周期生殖激素变化及卵巢卵泡发育规律的研究

为探究新疆伊犁鹅繁殖周期中血浆主要生殖激素、卵巢形态及卵泡发育的变化规律,试验以健康状况良好、体重相近的2岁伊犁鹅为试验对象,分别在产蛋期、就巢期及休产期各随机选取32只,采集1次血样,测定激素水平;在各时期分别选取5只采集卵巢组织,观测卵巢及卵泡发育情况。结果表明,在产蛋期,伊犁鹅的GnRH分别极显著高于就巢期和休产期16.78%和58.29%（P<0.01）;PRL显著低于就巢期13.00%（P<0.05）,极显著高于休产期28.94%（P<0.01）;FSH高于就巢期6.98%（P>0.05）,极显著高于休产期21.12%（P<0.01）;LH极显著低于就巢期8.38%（P<0.01）,极显著高于休产期16.84%（P<0.01）;E₂水平分别极显著高于就巢期和休产期29.80%和112.40%（P<0.01）;P₄水平分别极显著高于就巢期和休产期28.89%和30.34%（P<0.01）。产蛋期伊犁鹅的卵巢体积和重量均极显著大于就巢期和休产期（P<0.01）。产蛋期伊犁鹅成熟卵泡与就巢期和休产期相比明显较大,次级卵泡数量较多,初级卵泡数量较少;就巢期卵巢上生长及成熟卵泡发生闭锁,颗粒胞层收缩,向内凹陷,胞质出现空腔,各级卵泡出现萎缩;与就巢期相比,休产期卵巢上卵泡胞质空腔变大,向内凹陷程度进一步加深,大量原始卵泡均匀排列。由此可见,在产蛋期,伊犁鹅的GnRH、E₂、LH反应活跃,对卵巢卵泡发育起主导作用;在就巢期,PRL、LH维持较高的分泌水平,协同维持就巢。     

Gene expression profiling in embryonic chicken ovary during asymmetric development

The reproductive system in female birds arises as bilateral asymmetrical anlagen, excluding the birds of prey. Earlier, histological and messenger RNA (mRNA) expression profile studies of several genes related to gonadal sex differentiation in chicken embryos tried to elucidate the query of this asymmetry in a scattered manner. To understand the matter precisely, we have focused on mRNA expression of a cohort of genes (FSHR, CYP19A1, caspase 3, caspase 8) in second half of the embryonic days (E10–E18). The established role of leptin in development of the embryo and its expression in the embryonic ovary also drove us to check leptin receptor (LEPR) expression in the ovary. Increased expression of FSHR and CYP19A1 in the left ovary compared with that in the right ovary was identified (P < 0.05), promoting preferential left ovarian development and functionality. Significant high expression (P < 0.05) of the apoptotic genes in the right ovary were also involved here. Leptin probably has no direct influence on ovarian asymmetry as no significant variation in gonadal mRNA expression of LEPR was observed within the same experimental days. We propose that asymmetric expression of this cohort of genes (FSHR, CYP19A1, caspase 3, caspase 8) leads to the development of dimorphic gonads during embryogenesis.