Effect of Suppression of FSH with a GnRH Antagonist (Acyline) Before and During Follicle Deviation in the Mare

A GnRH antagonist (Acyline) was used to study the role of FSH in early development of a follicular wave in 61 mares. In Experiment 1, a single dose of 3 mg per mare, compared with 0 and 1 mg, suppressed both the FSH and follicle responses to exogenous GnRH. In Experiment 2, high concentrations of FSH were induced by two successive ablations of all follicles ≥ 6 mm on days 10 and 13 (day 0 = ovulation). A single treatment with Acyline resulted in significantly greater suppression of plasma concentrations of FSH than a single treatment with charcoal-extracted follicular fluid (source of inhibin) or oestradiol. Suppression of FSH was not significantly different between the group treated with Acyline alone and a group treated with a combination of Acyline, inhibin and oestradiol. In Experiment 3, all follicles were ablated on day 10 to induce an FSH surge and a new follicular wave. Acyline treatment on day 10 resulted in an immediate decrease in FSH, without a significant effect on day of emergence of a new wave or growth of follicles from 7 to 11 mm on days 11–13. Treatment on day 15, a day before expected follicle deviation and after the peak of the wave-stimulating FSH surge, resulted in an immediate decrease in FSH and cessation of follicle growth. Results indicated that growth of follicles for about 2 days after wave emergence was independent of FSH. In contrast, during the decline in the wave-stimulating FSH surge and before follicle deviation, growth of follicles was dependent on FSH.     

内蒙古绒山羊次级毛囊及其毛囊群结构的形态发生规律研究

以Ed70～150内蒙古绒山羊胚胎和一月龄羊羔的体侧部皮肤作为研究材料,通过石蜡切片和HE染色,研究内蒙古绒山羊胚胎期次级毛囊的群落结构以及形态发生规律.结果表明,内蒙古绒山羊次级毛囊（S0）的形态发生大约开始于Ed75表皮,位于初级毛囊的锐角侧,衍生次级毛囊（SD）以两种方式持续发生,出生后衍生次级毛囊发生更加活跃,最终构成三元结构毛囊群中的次级毛囊团;内蒙古绒山羊次级毛囊（S0）的形态发生从启动到成熟可划分为9个时期：毛基板前期、基板期、毛芽期、毛钉1～2期、毛囊1～4期;典型的三元结构毛囊群的初级毛囊在次级毛囊发生之前直径均一,此后因初级毛囊的夹角间发生次级毛囊,整个毛囊群被结缔组织膜包围,形成毛囊群,随着次级毛囊数目的增多,三元结构中两侧的初级毛囊直径变小,衍生次级毛囊发生越晚直径越小.     

羊胎儿期皮肤毛囊发育及调控机制的研究概述

中国绵山羊养殖历史悠久,品种资源丰富,在国民经济中起重要作用。羊毛按纤维类型可分为同质毛和异质毛,同质毛的特点是被毛由同一类型的羊毛纤维组成,其特点是羊毛的纤维直径、长度、卷曲等外表特征基本相同,异质毛的特点是被毛中兼有绒毛、有髓毛、无卷曲和少卷毛等不同类型的羊毛纤维,其化学、物理性能均不相同。毛囊是控制哺乳动物被毛生长的重要器官,是唯一具有周期性发育并可终生再生的器官,控制着被毛发生发育与自然脱落。毛囊依据其形成时间和结构可分为初级毛囊(primary follicles)和次级毛囊(secondary follicles),初级毛囊生长髓质发达的粗毛,次级毛囊产生无髓毛的绒毛。有髓毛较粗长且弯曲少,多用于加工粗纺织品、毛毯、地毯、毡制品;无髓毛直径一般不超40 μm,弯曲多,是毛纺工业的优质原料。毛囊的发育受到不同信号通路和基因的影响,如Wnt信号通路、骨形态发生蛋白质(BMP)信号通路、成纤维细胞生长因子(FGF)信号通路、音猬因子(SHH)信号通路、Notch信号通路等以及角蛋白家族基因、BMPs家族基因、同源异型盒基因(Hox)等。作者对国内外对绵山羊胎儿期皮肤毛囊发育及调控机制进行综述,以期为提高以绵山羊被毛产量及改善被毛品质为主要育种目标的选育提供参考。     

绵羊毛囊及其角蛋白研究进展

毛囊是毛纤维的生长基础,决定毛纤维的性状,角蛋白是毛囊组成的重要成分之一。近年来,对毛囊生长发育和角蛋白基因的挖掘等取得了一定的进展。文章回顾了绵羊角蛋白基因的发现,已经与人类角蛋白基因相当,但在数量和分类上存在差异;笔者介绍了绵羊毛囊的形态学结构,简述了毛囊角蛋白基因的表达定位和影响毛纤维性状的角蛋白,并分析了毛囊中的蛋白质组学技术的应用对毛囊生长发育和毛纤维性状的重要作用,以期为绵羊毛囊生长发育和羊毛性状的分子选育提供新的研究思路。     

绵羊毛囊及其角蛋白研究进展

毛囊是毛纤维的生长基础,决定毛纤维的性状,角蛋白是毛囊组成的重要成分之一。近年来,对毛囊生长发育和角蛋白基因的挖掘等取得了一定的进展。文章回顾了绵羊角蛋白基因的发现,已经与人类角蛋白基因相当,但在数量和分类上存在差异;笔者介绍了绵羊毛囊的形态学结构,简述了毛囊角蛋白基因的表达定位和影响毛纤维性状的角蛋白,并分析了毛囊中的蛋白质组学技术的应用对毛囊生长发育和毛纤维性状的重要作用,以期为绵羊毛囊生长发育和羊毛性状的分子选育提供新的研究思路。     

Changes in follicular vascularity during the first follicular wave in lactating cows

Increase in the blood supply to individual follicles appears to be associated with follicular growth rates and the ability to become the dominant follicle, while reduced thecal vascularity appears to be closely associated with follicular atresia. Therefore, this study aimed to determine the real-time changes in the vascularity of the follicle wall during the first follicular wave in cycling Holstein cows. Normally cycling and lactating cows (n=5) were examined by transrectal color Doppler ultrasonography (the sensitivity for velocity: > 2 mm/sec) to determine the changes in the vasculature of the follicle wall (presence or absence of blood flow) and the diameter of follicles. A new follicular wave and ovulation were induced by GnRH injection at 48 h after an injection of PGF2alpha analogue. The ovaries were scanned daily for 7 days after GnRH injection. Follicles >2.5 mm were classified into 3 groups by the changes in diameter as follows: 1) largest follicle, 2) second largest follicle, and 3) small follicles, which included all other follicles >2.5 mm. Before the follicle selection, there was no significant difference in the percentage of follicles with detectable blood flow between the subsequently determined largest and second largest follicles. After the follicle selection, the percentage of follicles with detectable blood flow significantly decreased among the second largest follicles. In addition, small follicles with detectable blood flow kept larger diameters than those without detectable blood flow from one day before the occurrence of follicle selection. It is likely that maintenance of follicle vasculature and appropriate blood supply to the larger follicles is essential for follicle dominance. In small follicles, the presence of blood flow within the wall also appears to be required for recruitment. Consequently, the data suggest that the change of the blood supply to an individual follicle closely relates to the dynamics of follicular growth in the first follicular wave in the cow.     

Xenografting of bovine secondary follicles into ovariectomized female severe combined immunodeficient mice

Xenografting of ovarian tissue into immunodeficient mice has been used as a model to study the dynamics of follicular development and provides an alternative method for the production of mature oocytes. In a previous experiment, we demonstrated that xenografted bovine secondary follicles developed to the antral stage in severe combined immunodeficient (SCID) mice. In the present study, we examined the development of bovine secondary follicles (140-190 microm in diameter) grafted into ovariectomized mice in comparison with intact female mice as a control. At 4 weeks after grafting, several antral follicles ranging from 350 to 550 microm (457.6 +/- 50.8 microm) in diameter were found in the control mice, while a single large (larger than 2.5 mm) antral follicle and other small follicles were observed in every ovariectomized mouse. At 6 weeks after grafting, the mean diameter of morphologically normal follicles had further increased in the control group (591.8 +/- 132.0 microm). In ovariectomized mice, however, the mean diameter of follicles decreased (4 weeks: 864.2 +/- 988.2 microm; 6 weeks: 496.5 +/- 137.6 microm), since the single large antral follicle observed at 4 weeks had degenerated by 6 weeks. In control mice, more than 70% of follicles were morphologically normal and formed an antrum, and most of the follicles contained morphologically normal oocytes which grew to 122.5 +/- 2.2 microm. In ovariectomized mice, morphologically normal oocytes also grew larger than before grafting, but their survival rate was significantly lower than that in control mice. These results suggest that ovariectomy of host mice alters the developmental pattern of xenografted bovine secondary follicles to accelerate a single follicle to develop in the graft.     

基于单细胞转录组测序技术对鄂尔多斯细毛羊次级毛囊形态发生诱导期的研究

【目的】试验旨在解析鄂尔多斯细毛羊胚胎期次级毛囊诱导期形态发生过程中主要细胞类型的分子特征和分化过程。【方法】对采集的3只鄂尔多斯细毛羊(胎龄87 d)体侧部(肩胛骨后缘处)的皮肤样本进行HE染色,鉴定毛囊的发育时期;部分皮肤样本经过混样后进行单细胞转录组测序(scRNA-Seq),应用t-分布随机近邻嵌入(tSNE)分析细胞簇,分别使用胶原Ⅰ型α1链(Col1a1)和角蛋白15(Krt15)鉴定真皮谱系细胞和表皮谱系细胞,并使用皮肤组织不同细胞的标记基因进行细胞类型分析;对测序数据进行拟时序分析,探究其分化过程中差异基因的表达;通过GO功能富集分析进一步验证基因的功能。【结果】HE染色结果发现,鄂尔多斯细毛羊在胎龄87 d处于次级毛囊诱导期。通过scRNA-Seq在胎龄87 d的细毛羊体侧部皮肤细胞样品中获得10 603个细胞和18 704个基因的scRNA-Seq数据可用于下游分析。tSNE分析发现,皮肤组织中共有15个细胞簇;Col1a1和Krt15标记基因鉴定表明,真皮细胞和表皮细胞具有高度异质性。拟时序分析构建毛囊形态发生过程中真皮/表皮细胞谱系细胞的分化轨迹和基因动态表达图...     

Changes in plasma follicle-stimulating hormone, luteinizing hormone, estrogen and progesterone during growth of ovulatory follicles in the pig

This experiment was conducted to determine the changes in secretion of LH, FSH, estrogen and progesterone during follicle maturation. Ovaries were recovered from 11 non-treated (control) gilts, three on day 13, four on day 16, and four on day 19 of the estrous cycle, and from four altrenogest-treated gilts on day 19. Altrenogest, a progesterone agonist, was fed at a dose of 20 mg once daily from days 13 to 18 to block spontaneous follicle maturation. Gilts were bled daily from day 12 until slaughter. For control gilts, the number of follicles/gilt 1-6 mm in diameter decreased (P less than .05) from 93.5 on day 13 to 21.5 on day 19, and the number of large (greater than 6 mm) follicles increased (P less than .05) from 5.3 to 13.2. Altrenogest treatment blocked loss of small follicles and growth of large follicles between days 13 and 19. Plasma progesterone decreased (P less than .001) between days 12 and 16 in both control and altrenogest-treated gilts. Plasma FSH decreased (P less than .05) between days 12 and 16 only in control gilts. Plasma LH was not significantly affected by day or altrenogest treatment. Plasma estrogen increased (P less than .05) between days 15 and 19 only in control gilts. These results indicate that 1) no increased LH secretion was detected in conjunction with emergence of ovulatory follicles, and 2) atresia of nonovulatory follicles was associated with decreased secretion of FSH. Both atresia and decreasing FSH secretion began before estrogen concentration increased in the systemic circulation.     

催乳素对内蒙古绒山羊毛囊体外培养影响的研究

【目的】 研究催乳素（PRL）对内蒙古绒山羊初级毛囊和次级毛囊体外生长及形态变化的影响。【方法】 机械法结合切割法分离内蒙古绒山羊的初级毛囊和次级毛囊,在初级毛囊培养液中分别添加0、5、10、50、100 ng/mL催乳素进行体外培养,每组24根,共培养5 d,每天在显微镜下观察其形态并拍照,统计其生长长度、生长速度和存活率,筛选出最适催乳素处理浓度。然后将初级毛囊与次级毛囊分别分为初级毛囊对照组（PF-K）、初级毛囊试验组（PF-PRL）、次级毛囊对照组（SF-K）、次级毛囊试验组（SF-PRL）,每组24根,对照组用基础培养液培养,试验组在基础培养液中添加最适浓度的催乳素,培养5 d,每天观察毛囊的形态并拍照,同时测量各组毛囊的生长长度。【结果】 10 ng/mL催乳素组毛囊的平均日生长长度均极显著高于其他浓度组（P<0.01）,最终生长长度和存活率均最高,因此,后续试验选择10 ng/mL催乳素处理毛囊。试验组和对照组初/次级毛囊的毛干与根鞘部位同时伸长,随着培养时间的增加均出现不同程度的弯曲。PF-PRL、SF-PRL组毛囊在2~5 d的总长度分别极显著高于PF-K、SF-K组（P<0.01）。PF-K组除第1天与第0天差异不显著外,1~5 d毛囊的总长度依次显著增加（P<0.05）;PF-PRL组0~5 d毛囊的总长度依次显著增加（P<0.05）。SF-K组毛囊第5天的总长度显著高于0~4 d （P<0.05）;SF-PRL组第4、5天毛囊的总长度均显著高于0~3 d （P<0.05）,第3天毛囊的总长度显著高于0~2 d （P<0.05）。PF-PRL、SF-PRL组毛囊在2~5 d的平均日生长长度分别极显著高于PF-K、SF-K组（P<0.01）。【结论】 10 ng/mL催乳素是体外促进毛囊生长的最适浓度,10 ng/mL催乳素对体外培养的内蒙古绒山羊的初级毛囊和次级毛囊均有极显著的促生长作用。     

Characterization of transport systems for cysteine, lysine, alanine, and leucine in wool follicles of sheep

Aspects of the uptake of the AA Cys, Leu, Ala, and Lys into wool follicles were investigated using short-term culture of thin strips of sheep skin. Following verification of the reliability of the model system, the sites of uptake of the radiolabeled AA were shown to differ and to be consistent with their different roles in fiber production. Cysteine appeared in the zone of keratinization immediately distal to the follicle bulb. Lysine was incorporated into the germinative cells of the follicle bulb and the cells of the inner root sheath. Leucine and Ala were incorporated into the follicle bulb, inner root sheath, and keratinizing fiber. The incorporation of all AA into the dermal papilla was low. The relative rates of uptake of the AA into the wool follicle were as follows: L-Cys (100), L-Leu (5.5), L-Ala (2.5), and L-Lys (0.8). Uptake of Cys was saturable and followed Michaelis-Menten kinetics, suggesting a carrier-mediated system, with little or no diffusion. The majority (70%) of Cys uptake into follicles was via a Na-independent system that was not inhibited by alpha-(methyl-amino)isobutyric acid or 2-amino-2-norbonanecarboxylic acid and therefore is not via the normal Cys transport systems A, ASC, or L. Uptake of Cys appeared to be via a low-affinity, high-capacity transport system, which may be unique to the fiber-producing follicle. The majority of Ala transport had characteristics consistent with the functioning of system A (Na-dependent, inhibited by alpha-(methylamino)isobutyric acid, and low substrate affinity). Leucine uptake was inhibited by 2-amino-2-norbonanecarboxylic acid but was Na-dependent, suggesting that a variant of system L operates in the follicle to transport Leu. Lysine uptake was consistent with the operation of the usual Lys transporter system y+. Diets designed to maximize wool growth should provide AA profiles reflecting the relative rates of uptake demonstrated in this study. Investigations of possible polymorphisms in genes encoding AA transport proteins in follicles may reveal a source of genetic differences in wool growth potential among genotypes.     

绒山羊次级毛囊基因表达滞后性的转录组分析

毛囊是具有高度的自我更新能力、独特的可再生器官,其周期性变化是一个动态过程,为了研究毛囊差异基因表达变化情况,文章以内蒙古绒山羊生长期毛囊为研究对象,利用Illumina高通量测序技术方法,检测6~10月皮肤毛囊差异基因表达变化情况,寻找对绒毛生长及质量具有调控作用的特异表达基因。试验发现,多数差异基因分别在初级毛囊（PF）的7、8月份和次级毛囊的（SF）8、9月份表达;在绒毛生长期的相邻月份中,发现FAM83C、LOC102185501、FYCO1、CTTNBP2NL、C6orf132、KRTAP29-1 和 CRYBG3 7个共同差异表达基因呈现相同的表达趋势,且在次级毛囊上的表达变化均比初级毛囊滞后1个月。综上所述,次级毛囊在基因表达调控中存在一定的滞后性,这将为绒毛周期生长发育和分子育种提供重要的理论基础。     

Ovarian Follicular Dynamics of five-eighths Girolando Cows

The objective of this study was to examine the follicular dynamics of five-eighths Girolando cows by observing the number of follicular development waves, days of emergence of those waves, diameters of the dominant and largest subordinate follicles and the processes of follicular selection and dominance. Ovarian follicle dynamics were monitored for 24 oestrous cycles in 12 cows, of 4 to 10 years of age, presenting regular oestrous cycles and with body scores between 3 and 4. Ovaries were observed daily for two consecutive oestrous cycles and follicles were measured with ultrasonographic equipment. The dominant follicle was considered to be that which presented a diameter ≥ 10 mm for three consecutive days and on the day of wave emergence, when a group of follicles measuring 3–5 mm in diameter would appear. Of the 24 cycles monitored, 62.5% presented two waves of follicular development and 37.5% presented three waves. The cycles presenting two waves had an average duration of 20 days, with the emergence of the waves on days 1 and 9, whereas the cycles presenting three waves had an average duration of 22 days, with emergences on days 1, 10 and 16. For cycles with two waves, both the first and second dominant follicles reached an average size of 13.8 mm, with the first regressing on day 10 and the second ovulating around day 20. For cycles with three waves, the dominant follicles of the first and second waves reached maximum diameters of 11.8 and 12 mm, respectively, with the first regressing on day 11 and the second regressing on day 17. The third dominant follicle reached a maximum diameter of 12.4 mm on day 20, and ovulated on day 22. These results lead to the conclusion that the follicular dynamics of five-eighths Girolando cows are characterized by the presence of two to three waves of follicular growth.     

不同颜色LED光对苏系长毛兔毛品质及皮肤毛囊发育的影响

本试验拟研究LED光照对苏系长毛兔毛品质及皮肤毛囊发育的影响。试验选择3月龄健康、体重相近（（2.245±0.296） kg）的50只苏系长毛兔,随机分为5个处理组,即LED红光组、LED绿光组、LED蓝光组、黑暗组和对照组（自然光组）,每组5个重复,每个重复2只。采用16L∶8D光照制度,光照强度50 lx,试验期73 d。试验末采集毛样测定毛品质,采集血液测定激素指标,采集皮肤组织观察毛囊发育。结果表明：1） LED光照对长毛兔终末体重、平均日增重（ADG）、采食量无显著的影响（P>0.05）,但红光组提高了长毛兔的毛产量,高于对照、绿光、黑暗组（P=0.050）。2）红光组显著提高肩胛部的毛纤维长度,比对照组和绿光组长35.36%（P<0.05）。红光组显著降低了粗毛率,显著低于绿光组（P<0.05）。对照组粗毛细度显著小于绿光组和黑暗组（P<0.05）,各组间细毛细度无显著性差异（P>0.05）,但红光组最细。回潮率各组之间均无显著差异（P>0.05）。3）与对照组相比,红光组能显著提高血清褪黑激素（MT）、三碘甲状原氨酸（T₃）的浓度（P<0.05）,黑暗组显著降低催乳素（PRL）的浓度（P<0.05）。4）组织切片观察发现,红光毛囊群个数最多（16.5）,且多为次级毛囊,初级毛囊极少,毛囊分布均匀;对照、蓝光、黑暗组毛囊群结构处于正常水平;绿光组毛囊群个数最少（10.0）,毛囊分布不均。LED红光可以促进机体MT的分泌,提高苏系长毛兔皮肤组织毛囊群数和次级毛囊数,进而改善毛纤维品质。     

Follicular fluid concentration of transforming growth factor-beta1 is negatively correlated with estradiol and follicle size at the early stage of development of the first-wave cohort of bovine ovarian follicles

The objectives of this study were to characterize the relationship between estradiol and transforming growth factor-β1(TGF-β1) concentrations in follicular fluid of growing bovine ovarian follicles, and to examine the effect of TGF-β1 on FSH-stimulated estradiol secretion in cultured bovine granulosa cells. Follicular fluid was collected from individual follicles >5 mm in diameter by ultrasound-guided transvaginal puncture (n = 12 heifers). Follicles were sampled at four different stages of development of the first post-ovulatory wave during selection of the single dominant follicle. Estradiol, progesterone and total TGF-β1 were measured in follicular fluid of the three or four largest follicles sampled when the largest follicle (F1) had reached either 6.5, 7.5, 8.5 or 9.5 ± 0.5 mm stage of development. There was a significant negative relationship between follicular fluid TGF-β1 and estradiol concentrations (R² = 0.44; p < 0.002), and between TGF-β1 concentrations and follicle diameter (R² = 0.23; p < 0.01) in cohort follicles at the 6.5 mm stage, but not at any later stage of development of the follicle wave. There was no correlation between progesterone and TGF-β1 concentrations at any stage. To assess the causal relationship between TGF-β1 and estradiol, granulosa cells from follicles measuring 2–5 mm at dissection were placed in serum-free culture. TGF-β1 caused a dose-dependent decrease in FSH-stimulated estradiol secretion (P < 0.001). These findings suggest that TGF-β1 has an inhibitory effect on estradiol secretion in FSH-stimulated follicles and that a reduction in TGF-β1 inhibition may be part of the mechanism of selection of a single dominant follicle.     

Ovarian laying hen follicular maturation and in vitro Salmonella internalization

Transovarian transmission of paratyphoid Salmonella is well documented and occurs at a low incidence in chickens. However, the exact mechanism of follicular invasion is not well understood. The following study investigates the ability of Salmonella to invade ovarian follicles at different stages of follicular maturity in vitro. Ovarian follicles were collected from Leghorn hens and separated into three stages of maturity: (1) large yellow follicles or F follicles (LYF), (2) small yellow follicles (SYF), and (3) small white follicles (SWF). All follicles were incubated at 37 degrees C in RPMI 1640 medium. Follicles were incubated with 1 x 10(6) CFU/mL of Salmonella typhimurium and Salmonella enteritidis sensitive to gentamicin for 2 h. Samples were then removed from the bacterial culture, and placed in medium containing gentamicin sulfate for 5 h to kill any S. typhimurium or S. enteritidis, which had not invaded the follicular membrane. After the 5 h incubation, follicles were stomached in phosphate buffered saline. Serial dilutions were made of each follicle and viable S. typhimurium and S. enteritidis cells were enumerated on brilliant green agar. Two identical trials were conducted. Data suggest that Salmonella may differentially invade ovarian follicles depending on maturity of the follicle, and that SWF may be more susceptible to S. typhimurium and S. enteritidis invasion than either the SYF or the LYF.     

Recruitment and selection of ovarian follicles for determination of ovulation rate in the pig

Gonadotropins determine the follicle selection and ovulation rate. Follicle growth is independent of gonadotropins until antrum formation, at which time recruitment occurs. Once recruited, follicles will continue to grow or degenerate. In gilts, visible surface follicles are classified as small (<3mm), medium (3-6.9 mm) and large (> or =7.0mm). At estrus (day 0), there are approximately 15 small and medium follicles, and approximately 15 large follicles. By day 3, there may be approximately 30 small, 5 medium and no large follicles. During the remainder of the luteal phase, the pool of follicles increases and peaks at day 11-13 with approximately 50 small, and 30 medium, but with no large follicles observed. By the start of the follicular phase at day 15, numbers of small and medium follicles rapidly decline, while a pool of medium follicles is selected for the ovulation. The size of large follicles at estrus is heterogeneous (6.5-10.0 mm) but their number is reflective of the subsequent number of corpora lutea found following the ovulation. However, the time of medium follicle selection for ovulation is variable during the late luteal and early follicular phases. Suppression of FSH before and at the time of luteolysis reduces medium and large follicles but does not reduce the ovulation rate. In contrast, suppression of FSH for 3 days or unilateral ovariectomy after 3 days of the follicular phase prevents full ovulatory compensation. Therefore, FSH appears to be involved in the maintenance of a pool of medium follicles that can be selected by LH to mature and ovulate.     

Effects of long-term grafting on follicular growth in porcine ovarian cortical grafts xenoplanted to severe combined immunodeficient (SCID) mice

To establish a tool for the study of follicular growth and development, we xenotransplanted small pieces (approximately 1 mm3) of porcine ovarian cortical tissues containing only primordial follicles and small preantral follicles under the capsules of kidneys of severe combined immunodeficient (SCID) mice (8-10 weeks old). The changes in cell proliferation and cell death/apoptosis, and vascularization in xenotransplanted follicles during follicular growth and development were analyzed histochemically at 1-26 weeks after operation. Follicles in grafted ovarian tissues grew rapidly forming an antral cavity (a hallmark of tertiary follicles) at 1 week after grafting. The diameter of the follicles in transplanted tissues ranged from 0.5 to 1.5 mm, from 0.5 to 2.0 mm and from 0.5 to 3.0 mm at 1, 2 and 26 weeks after the operation, respectively. Histological observation of ovarian tissues at 26 weeks after grafting revealed that all grafts had abundant capillary vessels, which invaded from murine organs and surrounded the growing follicles. Grafted small preantral follicles developed to the antral stages at 1 week after grafting and growing antral follicles survived at 26 weeks after grafting. The oocytes in the growing follicles were easily recovered for evaluating the quality. Our simple xenografting system is easy to use and a good experimental tool for the study of folliclular growth and development in porcine ovaries.     

毛囊发育与周期性生长的调控信号通路研究进展

毛囊是皮肤的重要附属结构,也是控制哺乳动物被毛生长的重要器官.哺乳动物出生后,毛囊具有终生呈周期性生长的特性,毛囊干细胞、毛乳头细胞、毛母质细胞及脂肪细胞等参与了毛囊周期性生长,Wnt、BMP、Notch等信号通路与毛囊生长发育密切相关.本文从哺乳动物毛囊的结构、周期性生长特征以及参与毛囊周期性生长调控的相关信号通路等...