除去精浆对内蒙古白绒山羊精液冷冻保存效果的研究

采用阿尔巴斯白绒山羊精液,用三种不同离心方法洗涤除去精浆后,对精液进行冷冻处理,结果表明750rpm/min一次或两次离心除精浆,精子冷冻解冻后的活率,质膜完整率,线粒体活性显著高于对照组（P＜0.05）。750rpm/min一次离心处理后顶体完整率显著高于750rpm/min两次离心处理。1500rpm/min一次离心处理后,精子冷冻解冻后的的活率,顶替完整率,线粒体活性显著（P＜0.05）低于其它各组,解冻后活率与对照组无显著差异。这是由于离心速度的偏高会对精子形成一定的机械损伤。     

环境因子对鼠尾藻生殖托生长及光合特性的影响

鼠尾藻(Sargassum thunbergii)样本采自青岛太平角, 以光照、温度、盐度及营养盐水平4项环境因子分别设置4组单因素实验, 研究其对鼠尾藻生殖托的生长、表观光合作用、暗呼吸作用以及色素积累的影响。结果显示: (1)光照度为8 000 lx、温度为20℃和盐度为20的条件下生殖托的比生长速率(SGR)较大, 表观光合作用较强。光照12 000 lx抑制生殖托的光合作用与生长, 15℃下比生长速率比20℃小50.64%(P<0.05), 盐度从31下降到28, 比生长速率与表观光合速率显著增大。(2)色素含量与光照度、温度呈显著的负相关性, 叶绿素a和类胡萝卜素含量受环境因子影响较大, 而叶绿素c相对稳定。(3)氮磷营养盐的浓度配比对生殖托的生长、光合作用影响显著, 适宜的氮磷比(N/P)范围为5∶1~1∶1, 而50∶1显著抑制生殖托的生长。(4)相比氮元素而言, 磷浓度变化对生殖托光合作用影响更大, 说明磷元素对于生殖托的构建至关重要。(5)氮磷比对生殖托色素含量影响不显著, 而富氮、富磷培养液有利于色素的积累。结果表明, 上述4项环境因子对鼠尾藻生殖托的生长及光合特性均有显著影响, 适宜的培养条件为光照度8 000 lx、温度20℃、盐度20、氮磷浓度比(N/P)在5∶1~1∶1。本研究旨在为鼠尾藻人工育苗技术的优化提供科学依据。

     

水分从玉米根端输往体内途径的探讨

从玉米各层根中的一条吸入染料溶液后追索其输往地上各器官的踪迹。从 n 层节根可输往叶片范围为≥n 节可见叶。主胚根输往各叶全部纵向大脉,次生胚根每条只输往各叶的50%纵向大脉,各层节根从不同方向输入后,各自通向相应叶片的特定部位。在茎内,每一条节根吸水后,一般在输入方向的一个局部内上升,输入节位愈高,上升途径愈靠     

Seasonal variations in the morphology of the seminal vesicles of the African straw-coloured fruit bat (Eidolon helvum)

The study investigated seasonal changes in the morphology of the seminal vesicles of Eidolon helvum in a typical African tropical environment. Seminal vesicles of forty-eight bats were examined during the early rainy, late rainy and peak dry seasons, using gross anatomical, histological and ultrastructural techniques. The interlobular connective tissue septa from the external capsule demarcated the glandular parenchyma into numerous lobules of tubulo-alveolar glands. A simple cuboidal epithelium of mono- or bi-nucleated cuboidal cells lined the glandular mucosa during the rainy season. This was replaced by a bistratified cuboidal epithelium, whose upper layer of cells showed evidence of degeneration, during the dry season. The PAS-positive secretory products appeared to be numerous during the rainy season, but few and clumped together during the dry season. The mean gross weight, interlobular septal thickness, acini diameter and epithelial height of the glands varied significantly with season. Ultrastructural features of the secretory cells during the rainy season showed well-developed cytoplasmic organelles, numerous electron lucid secretory vesicles and electron-dense granules. Secretory epithelial cells of the seminal vesicles are very active during the rainy season, while regeneration of degenerated epithelium in preparation for the next reproductive cycle occurs during the dry season.     

Changes in root length at the reproductive stage of maize plants grown in the field and quartz sand

The aims of this work were to investigate possible reasons for root mortality of maize plants at the reproductive stage and relationships between root mortality and internal sugar and external nitrogen (N) supply. Maize (Zea mays L.) plants were grown in the field in fertile soil and in a greenhouse in quartz sand with sufficient or deficient N supply. Deficient N supply reduced plant growth and total N uptake by 38% and 52%, respectively. The lengths of the seminal roots and of the early initiated adventitious roots of the first two whorls declined after reaching their maximum values before silking, no matter whether the plants were grown in the field or in quartz sand in the greenhouse. The lengths of the adventitious roots from higher nodes of plants grown in quartz sand, irrespective of N supply, did not decrease at the reproductive stage despite of decreasing sugar concentrations. In contrast, under field conditions, the length of adventitious roots from higher nodes decreased during grain filling. Total activity of all roots of greenhouse‐grown plants as deduced from translocation of N and cytokinins in the xylem exudate reached peak values at the end of the growing period, whereas in field‐grown plants N translocation decreased and cytokinin translocation did not change toward the end of the growing period. The results indicate that the pattern of root growth and mortality of maize plants in the reproductive stage was not affected by external N supply. Differences between glasshouse‐ and field‐grown plants are possibly due to effects of soil biota, which have to be further studied.     

Cryopreservation of semen from a stallion with seminal vesiculitis

A 6‐year‐old Warmblood stallion was admitted for semen collection and cryopreservation. On the seventh and subsequent collection days semen samples were contaminated with purulent debris. A diagnosis of seminal vesiculitis was made following ultrasonography and endoscopy of the seminal vesicles. The stallion was treated with systemic and topical antimicrobial therapy and, although this did not cure the condition, subsequent ejaculates were suitable for cryopreservation.     

锯缘青蟹雄性腹肢的结构和功能

于2000年6月至2002年10月,采用扫描电镜方法对锯缘青蟹（Scylla serrata）雄性附肢结构进行观察。结果表明,青蟹雄体输精管在第八胸节通向一个短的肌肉质的阴茎开口。第一腹肢由一个基部原肢和一个延长的内肢组成,表皮环包,形成一个交接管。第二腹肢吻合这个表皮管,而阴茎则放在内肢的基部侧面。交配时,阴茎在肌肉作用下,精液射到第一腹肢的射精管中,射出物在第二腹肢的活塞样的泵作用下,沿着管腔向里推进。第一腹肢顶端侧扁状、具侧缝,前部表面具棘突状和腺体孔,弯曲部棘较大。侧缝处具细长的棘和羽状刚毛,刚毛基部为杯状凹陷。     

Annual cyclic,and castration and cyproterone acetate-induced,changes in sialic acid content of the seminal vesicle of the catfish,Heteropneustes fossilis (Bloch)

In this study, the presence of sialic acid is demonstrated in the seminal vesicle (SV) of Heteropneustes fossilis. Sialic acid levels show an annual variation that was correlated with the secretory activity of the SV (expressed as the SV somatic index (SV-SI)) with the index being lowest in resting phase (January) and highest in spawning phase (July). Sialic acid was not detectable from November to March (resting to mid-preparatory phases). Castration (3 weeks) induced a significant rise in both SV-SI and SV sialic acid content possibly due to an elevated local production of androgens under the influence of increased gonadotropin secretion. Cyproterone acetate treatment caused a significant decrease in both SV-SI and SV sialic acid content. The results suggest that secretion of sialic acid in the SV is influenced by androgens and its measurement can be used as a simple and reliable index for quantitative assessment of the functional testicular state.     

Gonadotropin releasing hormone-analogue treatment increases sperm motility, seminal plasma pH and sperm production in yellowtail flounder Pleuronectes ferrugineus

Compared to control fish, gonadotropin releasing hormone-analogue (GnRHa) treatment delivered either by microspheres or cholesterol pellets successfully increased sperm production (cells kg–1) and milt volume (ml kg–1) in mature yellowtail flounder Pleuronectes ferrugineus during the spawning season. Spermatocrit decreased in both treated and control groups between 12 and 29 days post-implantation, indicating a seasonal decrease in sperm concentration, rather than an effect of the GnRHa treatments.Plasma levels of testosterone, 11-ketotestoterone and 17,20dihydroxy-4-pregnen-3-one (1720P) showed no clear pattern either across treatments or over days, however this does not exclude the possiblity that GnRHa had its effect on milt volumes via the stimulation of steroid production since the sampling protocol did not allow for the rapid clearance of steroids from the plasma. GnRHa treatment did not have a negative effect on sperm fertilizing ability, percentage hatch or larval morphology. Sperm motility and seminal plasma pH were increased by GnRHa treatment.     

Upregulation of CRISP-3 and kallikrein in stallion seminal plasma is associated with poor tolerance of cooled storage

For unknown reasons, stallion fertility and sperm longevity during cooled storage of semen vary markedly between individuals. Spermatozoa from individual stallions react differently to the presence, or the removal, of seminal plasma (SP). The aim was to evaluate differences in protein content in stallion seminal plasma with either a positive or a negative effect on sperm chromatin integrity during storage. Stallion semen samples from different ejaculate fractions were stored at 5°C for 24 hr. Sperm survival was assessed after storage using a sperm chromatin structure assay. Protein expression in SP with either positive or negative effects on sperm survival during storage was studied using two-dimensional differential gel electrophoresis and liquid chromatography–mass spectrometry. Lower sperm chromatin integrity was associated with upregulation of the proteins kallikrein, CRISP-3 and HSP-1, while higher chromatin integrity was associated with upregulation of TIMP-2. In the sperm-rich fractions, kallikrein and CRISP-3 differed significantly between SP samples with differing effects on sperm chromatin integrity. In the sperm-poor fractions, TIMP-2 and HSP-1 differed significantly between the two SP groups. Differences in the seminal plasma proteome are associated with sperm longevity during cooled storage.