一种有毒的游蛇——虎斑颈槽蛇

虎斑颈槽蛇是中国数量较多、分布最广的蛇类之一,但一直被当作无毒蛇而忽视。为了使人们对虎斑颈槽蛇有一个全面、正确的认识,也为以后的相关研究奠定一定的理论基础,从虎斑颈槽蛇的分布,形态,生活习性以及毒腺的研究等方面加以综述。     

爬行动物肾性节的研究概述

肾性节是一种雄性副性结构,主要存在于爬行动物双孔亚纲Diapsida鳞龙下纲Lepidosauria,尤其是有鳞目的雄性,由肾脏的集合管前端或肾单位的远曲小管末端膨大特化而成.肾性节的细胞由柱状上皮细胞组成,胞质中充满电子致密的分泌颗粒.组织化学研究表明,肾性节呈ACP、AKP、糖原、糖蛋白、脂类和蛋白质等反应阳性,且存在种间差异.肾性节的细胞大小和超微结构具有明显的年周变化,并与生殖腺的发育密切相关.此外,某些蛇和蜥蜴的雄性幼体具有肾性节,而在某些种类的雌性也具有类似的结构.有关这一结构的生理功能尚不完全清楚,曾有学者提出几种假设:具有支持和激活精子的作用,形成交配栓,与精液形成有关或提供求爱信息素等.     

室温条件下虎斑颈槽蛇卵的孵化与幼蛇饲养

目的探讨室温条件下虎斑颈槽蛇的孵化及幼蛇饲养情况。方法选用同一条虎斑颈槽蛇产的同窝蛇卵31枚,随机为A组（实验组）、B组（对照组）,A组16枚,B组15枚。两组蛇卵分别置于2个完全相同的打孔整理箱中进行孵化,孵出幼蛇用小泽蛙饲养。结果在室温条件下,孵化期58天,孵化率为96．77％。出壳后7～9天,幼蛇第1次蜕皮,蜕皮周期在11～16天不等。结论对虎斑颈槽蛇进行工厂化人工养殖是切实可行的。     

虎斑颈槽蛇多态与变异

目的研究虎斑颈槽蛇大陆亚种[Phabodophis tigrinus lateralis (Berthold)]在不同分布地区存在的多态现象和变异性。方法在分析已经报道的有关文献的基础上,研究辽宁、吉林等地野外采集到的标本,并对虎斑颈槽蛇大陆亚种的色斑变异和腹鳞的多态现象进行相关分析结果虎斑颈槽蛇大陆亚种的腹鳞数目与纬度呈强正相关,与经度呈中等正相关,与年均温度呈强负相关,与体长呈弱相关关系,年均温度高产卵时间早,而孵化时间长。结论分布范围相对较窄的蛇腹鳞数目是相对稳定的,分布范围广、跨越纬度大,腹鳞的数目差异亦很大。     

虎斑颈槽蛇中国大陆亚种颈背腺毒液的研究

虎斑颈槽蛇中国大陆亚种（Rhabdophis tigrinus lateralis）具有已知蛇类中罕见的颈背腺及其毒液。肉眼观察发现腺体呈珠球状,8～13对腺体呈平行排列,腺体间隔分布;组织切片观察发现,腺体上无开口,无合成毒液的细胞器;实验表明毒液有神经毒性,对小白鼠的半致死量（LD50）为97．99mg／kg,SDS-PAGE电泳呈现4条蛋白条带。虎斑颈槽蛇中国大陆亚种颈背腺毒液很可能作为一种特殊辅助防御系统,增强DuvemoY腺毒液的防御作用。     

嘉陵江下游蛇鮈的两性异形与雌性个体生殖力

为了解蛇鮈雌雄间是否存在显著的外部形态差异及雌性个体生殖力情况, 在繁殖期对嘉陵江下游(合川江段)共76尾蛇鮈样本的两性异形、性比及雌性个体生殖力进行分析.结果表明: 嘉陵江下游蛇鮈繁殖群体的性比接近1∶1,且蛇鮈两性的体型大小相同,但局部特征(如头部和躯干部等)呈现出显著的两性异形,如成体雄性蛇鮈的头部、胸鳍和腹鳍均较雌性蛇鮈大,而躯干部的体宽、体高和躯干长则是雌性蛇鮈大于雄性蛇鮈,这可能是性选择长期作用的结果.主成分分析显示,前3个主成分的累积贡献率达75.2%,但雌雄个体间形态特征相互重叠,无法将两者截然分开;利用判别函数对蛇鮈性别进行回判,综合判别准确率为92.1%.蛇鮈雌性个体绝对生殖力在979～19979粒;且与体长和去内脏体质量均呈显著正相关.同历史资料相比,本研究中嘉陵江蛇鮈的生殖力增大显著,这可能是蛇鮈对种群资源量下降和水环境变化主动适应的结果.     

虎斑颈槽蛇行为的观察

本文报道了虎斑颈槽蛇的行为。虎斑颈槽蛇一般栖息在水域附近。在辽宁省西部地区,１０月份陆续进入冬眠,翌年４月醒眠。以无尾两栖动物为食,采用偷袭和伏击方式捕食。有回缩、逃遁、藏匿和威吓等反捕行为。     

虎斑颈槽蛇大陆亚种的一些生物学资料

1990～2007年,对虎斑颈槽蛇的生活习性、生长发育、产卵、孵化条件和胚胎发育进行了观察研究.虎斑颈槽蛇的产卵期为6月～7月中旬,一年一次性产卵6～22枚, 孵化期为41～43天,胚胎发育分为16期.卵产出时胚胎已发育到第10～11期,孵化至37天时仔蛇已基本发育完全.详细描述了11～16期胎蛇的外部形态特征和发育时序.     

虎斑颈槽蛇Sox基因的克隆及测序

参照人SRY基因HMG-box保守区序列设计一对兼并引物,PCR扩增虎斑颈槽蛇的Sox基因,采用SSCP技术筛选阳性克隆,并对其进行了测序。结果表明：在雌雄个体中共筛选出3个Sox基因,其中一个为雄性独有,显示出性别差异性,3个Sox基因DNA序列及编码的氨基酸序列与人相应SOX3,SOX11,SOX22基因的相似性分别为91%,92%,91%和98%,96%,96%。显示出高度的保守性,实验结果为虎斑颈槽蛇的性别决定机制研究提供了分子资料。     

八种蛇(蛇亚目:游蛇科:颈槽蛇属)的半阴茎形态比较

蛇类半阴茎形态在研究蛇类的形态进化、分类和系统等方面具有重要的作用。对分布于我国境内的颈槽蛇属八种蛇(虎斑颈槽蛇、海南颈槽蛇、颈槽蛇、九龙颈槽蛇、缅甸颈槽蛇、黑纹颈槽蛇、喜山颈槽蛇和红脖颈槽蛇)的半阴茎进行详细描述和比较,并以此探讨部分物种的有效性和推断它们之间的进化及系统关系。     

Structure Organization of Urinary System in the Yellow Spotted Mountain Newts （Salamandridae： Neurergus microspilotus）

This study deals with the histomorphology of the mesonephros in male and female Neurergus microspilotus. The slender and narrow kidneys are positioned in the retro peritoneal position up against the ventral aspect of vertebral column and may extend the length from the esophagus-stomach junction to cloaca. The kidney in both sexes is composed of sexual（anterior） and pelvic（posterior） parts. The duct of sexual kidney is a narrow duct which is lying alongside its lateral edge. In the female, it is connected to the ureters and then the duct of defi nitive kidney. Before entering the cloaca, two ureters are joined together and open to the apex of the cloaca. In the male, after entering the sexual kidney, the sperm leave the testis through efferent ducts, then these ducts join together and eventually form Bidder＇s duct. The Bidder＇s duct joins the Bowman＇s capsule of the nephrons in the sexual kidney and the nephrons make collecting ducts which are fi lled with both sperm and urine. After leaving the kidney, all the collecting ducts are connected to the Wolffi an duct. Wolffi an duct joins the ureters（merge from defi nitive kidney） just before entering the cloaca. Based on serial paraffi n sections, nephrons consist of a fi ltration unit, the Malpighian corpuscle, and a renal tubule, which can be divided into 4 morphologically distinct segments： proximal tubule（first and second segment）, distal tubule, and collecting tubule. Collecting tubules merge and form a branch system that opens into collecting ducts.     

The sexual segment of hemidactylus turcicus and the evolution of sexual segment location in squamata

The kidneys of the Mediterranean Gecko, Hemidactylus turcicus (Gekkonidae), were investigated using light and electron microscopy with the primary focus placed on morphology of the sexual segment of the kidney. The nephrons of male H. turcicus are composed of five distinct regions: 1) a renal corpuscle and glomerulus, 2) a proximal convoluted tubule, 3) an intermediate segment, 4) a distal convoluted tubule, and 5) the sexual segment of the kidney/collecting duct. Female H. turcicus is similar but lack a sexual segment of the kidney. The sexual segment of the kidney is hypertrophied during the months of March through August, which corroborates previous reports of reproductive activity. During inactive months, the sexual segment of the kidney is nondiscernable from the collecting ducts. The sexual segment consists of tall columnar epithelial cells with basally positioned nuclei. Perinuclear Golgi complexes and rough endoplasmic reticulum are present. Secretory granules, which fill the apices of the epithelial cells, are electron dense and released into the lumen by a merocrine secretory process. Narrow intercellular canaliculi separate each epithelial cell and are sealed by tight junctions at the luminal aspect. Basally, leukoctyes are observed within the intercellular canaliculi and outside the basal lamina. Mast cells can be found just outside the basal lamina in close association with renal capillaries. The sexual segment of the kidney of H. turcicus is similar to that of three unrelated lizards for which ultrastructure was investigated with secretion mode being the major difference Also, H. turcicus is similar to most other lizards in that complete regression occurs during reproductive inactivity, but differs in this trait from the skink, Scincella lateralis, and most snakes which display a hypertrophied sexual segment of the kidney throughout the entire year. Although some unique similarities appear during the optimization, no direct patterns or directions are observed, and only the molecular based phylogeny resolves the ancestral condition of the Squamata as the sexual segment of the kidney being observed in the distal convoluted tubule, collecting duct, and ureter. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.     

Renal carbonic anhydrase in the quail Coturnix coturnix japonica: I. Activity and distribution in male and female metanephros

Summary Carbonic anhydrase activity was studied in the quail metanephros by means of histochemical, histophotometrical and biochemical methods. Male and female samples were examined separately in order to show sex-related differences in enzyme activity and localization. The staining patterns revealed differential distribution of reaction product in the different, tubular segments. The initial portion of proximal tubules showed positivity on the brush border in female kidneys only.Extra situ investigations provided further evidence of sexual dimorphism resulting in higher values of enzyme activity for female than for male kidneys.In both sexes, marked staining was detected at the distal tubule level where histophotometric analysis confirmed the highest amount of reaction product. Moreover, the intracellular staining distribution at this site proved to be similar to that observed for mammalian proximal convoluted tubules.In the collecting ducts, a mosaic-like pattern was found with respect to both carbonic anhydrase staining and metachromatic properties.The functional significance of the presence of enzyme in the different renal tubules is discussed by comparison with the mammalian kidney. A model is proposed whereby the distal tubules represent the main sites of urinary acidification and bicarbonate reabsorption.     

The kidney,adrenocortical homolog,and corpuscles of Stannius in the cockscomb pricklebackAnoplarchus purpurescens

The morphology of the kidney, adrenocortical homolog, and the corpuscles of Stannius was examined in the cockscomb prickleback,Anoplarchus purpurescens, a marine teleost which inhabits the intertidal zone. The paired kidneys of this fish are fused throughout most of their length, there is essentially a single posterior cardinal vein on the right side, they possess renal corpuscles, and there is no distal segment of the tubule. The tubule is specialized, in descending order, into ciliated neck and two proximal segments before entering the system of collecting tubules and ducts. The cells of the latter system are specialized for mucous secretion, as are cells of the main excretory ducts, the paired archinephric ducts. Tubulogenesis occurs in the kidneys in close apposition to the archinephric ducts. The presumptive adrenocortical homolog is located around the posterior cardinal veins in the head kidney while paired corpuscles of Stannius are confined to the posterior end of the kidney. All of the above features are consistent with those found in the kidneys of many other marine teleosts.     

虎斑颈槽蛇脑一氧化氮合酶NADPH-d组织化学定位研究

运用NADPH—d组织化学方法,对虎斑颈槽蛇脑的一氧化氮合酶进行了定位研究。结果表明：阳性反应主要位于脑的大脑半球、视上核、室旁核、联合下器官、内侧纵束、室旁灰质、蓝斑以及网状结构等区域,比较讨论了与其他脊椎动物的异同。分析一氧化氮作为神经信号分子除了参与各类动物共有的一些机能的调节以外,不同类群或种类中还参与某些特定生理功能的调节。     

17 alpha-oxidoreductase activity in kidneys of male and female mice of various ages

Male and female mice at 0-120 days of age were used. Homogenates of kidneys were incubated with [14C]4-androstene-3,17-dione, and 17 alpha-oxidoreductase activity per g tissue was examined. The activities of 17 alpha-oxidoreductase in the kidneys of both sexes increased markedly with age during sexual development by up to 150-fold and reached the maximum values (2700 and 1500 nmol/g/h in male and female kidneys, respectively) at 60 days of age. In the adult male mouse kidney, the activity in isolated cortex fractions was 14 times as high as the activity in isolated medulla fractions; in the medulla fractions renal tubules from the cortex accounted for 3-15% of the total tissue. Furthermore, histochemical examination showed the activity present only in the cortex, at which much higher levels in the tubules than in the glomerulus. Activity at 35-120 days of age was significantly higher in male kidneys than in female kidneys. The difference appears to be induced by testicular androgens during sexual development, since neonatal castration in males resulted in decreases of activity to levels similar to those in female kidneys. However, castration at 60 days of age showed no significant effect on the activity. The present results show that the activity per g tissue of 17 alpha-oxidoreductase in the mouse kidney increases markedly with age, and that the activity is largely confined to the renal tubules of the cortex.     

Development of the renal sexual segment in immature snakes: effect of sex steroid hormones

The renal sexual segment (RSS) of immature Northern and Diamondback Water Snakes and Red-Sided Garter Snakes exhibited varying responses to testosterone or 17beta-estradiol. In both male and female water snakes, kidney mass was not a reliable indicator of hormone treatment, whereas tubule diameter, epithelial height and number of sexual granules responded to hormone treatment. In male water snakes, either hormone initiated granule development by day 16; by day 23, only testosterone increased granule density. Female water snakes receiving either hormone exhibited a small number of granules by day 16; by day 23, granules increased only in Diamondback Water Snakes receiving testosterone. Hormones did not initiate RSS hypertrophy in female Red-Sided Garter Snakes. Tubule diameter and epithelial height of testosterone-treated males exhibited significant hypertrophy, while 17beta-estradiol initiated significant increases in tubule diameter. Garter snakes initiated sexual granule development in response to hormone treatment with males exhibiting a greater response than females and testosterone stimulating a greater response than 17beta-estradiol. Sex steroids appear to mimic sexual maturity in immature snakes initiating RSS development. Whereas the RSS of adult males respond to testosterone, our data suggest specific changes in the RSS of females during maturation effectively negates the effect of 17beta-estradiol evident in immature female RSS.     

Sulphamerazine toxicity in cut-throat trout broodfish Salmo clarki (Richardson)

Treatment of cut-throat trout broodfish Salmo clarki (Richardson) with Sulphamerazine at 220 mg/kg (10 g/100 1b) of fish/day for 14 days resulted in severe kidney histopathology and increased mortality among males. Experimental data presented showed that cut-throat trout broodfish were extremely sensitive to Sulphamerazine toxicity. Hydropic degeneration of renal tubule epithelium and haemorrhage into tubule lumens were observed in kidneys of both male and female trout, but was more severe in the former. Death, which occurred only in males, was correlated with spawning stress and impaired renal function.