猫儿山小鲵和瑶山肥螈消化道组织结构及 5-羟色胺细胞分布特征

为探讨猫儿山小鲵(Hynobius maoershanensis)和瑶山肥螈(Pachytriton intexpectatus)消化道结构的异同及5-羟色胺(5-HT)细胞的分布特征与食性、生活环境之间的关系,运用常规组织染色及免疫组织化学染色法对其消化道进行研究.结果 显示,猫儿山小鲵和瑶山肥螈的消化道均包括食道、...     

无斑肥螈皮肤的组织学观察

本文报导了无斑肥螈（Pachytriton labiatus）皮肤的显微结构和特点。其皮肤的基本结构与其他有尾两栖类相似,体背、腹部位的皮肤厚度和结构有一定差异,皮肤中有丰富的微血管,在表皮和真皮相接处分布密集,背部分布密度明显大于腹部。皮肤腺体较少,缺乏色素细胞,角质化程度较低,表皮细胞层数少,界限不清。表皮下的毛细血管常向表皮突起,突起处表皮细胞层数减少,形成皮肤的血气呼吸屏障,以保证皮肤有效的呼吸作用的完成。     

粤北南岭无斑肥螈的种群结构及食性

南岭山区的无斑肥螈 (Pachytritonlabiatus)主要分布于海拔 85 0m以上的山区溪流中 ,当雌性头体长 >5 5mm ,雄性头体长 >4 5mm时 ,卵巢和精巢分别开始明显发育 ;生殖时期为每年 9～ 1 0月份 ;数量呈明显下降趋势 ;主要食饵为环节、软体、节肢动物类。     

中国肥螈属(两栖纲:蝾螈科)一新种——弓斑肥螈Pachytriton archospotus sp. nov.

本文记述两栖纲蝾螈目蝾螈科一新种,新种具肥螈属(Pachytriton)系列特征,与肥螈属已知2种比较有明显区别.如1)本新种与黑斑肥螈(Pachytriton brevipes)相似,体表具黑色小圆斑,但新种具额鳞弓、上鳃骨直而与后者不同;无斑肥螈(Pachytriti on labiatus)(地模标本)虽具额鳞弓,但上鳃骨明显弯曲,体表无黑色小圆斑;2) 新种吻短,吻长小于眼间距,黑斑肥螈吻长大于眼间距,无斑肥螈吻长大于或等于眼间距, 它们的头型明显不同,虽然三者头长均大于头宽,但头长、吻长、眼间距差异显著;3)繁 殖期新种雄体肛区不明显肿胀,肛裂周边中、后部生殖乳突长,而且多,十分醒目;黑斑肥 螈和无斑肥螈繁殖期肛区明显肿胀膨大,生殖乳突较短、且稀.经统计分析三种肥螈的头体长、头长、头宽、吻长和眼间距存在显著差异     

镇海棘螈的精子结构

应用透射电镜和扫描电镜对镇海棘螈Echinotritonchinhaiensis精子的超微结构进行了研究。结果表明 :镇海棘螈的精子具有蝾螈科精子的一些共同特征 ,如精子头部较长、前端有顶体钩、细胞核周围有核脊、尾部轴丝旁有边缘丝 ,但也具有其自身的形态结构特点 ,如精子颈部的长度、核脊的形状和大小等与有尾两栖类物种的精子存在明显差别。镇海棘螈精子发达的颈部和丰富的核脊具类群特异性     

红瘰疣螈皮肤的显微结构观察

对我国Ⅱ级重点保护野生动物红瘰疣螈(Tylototriton shanjing)成体的皮肤结构进行了显微观察。观察结果表明,其皮肤厚薄、微血管、色素分布,以及腺体的分布和大小等方面在身体的不同部位存在差异:头和背部的皮肤厚于腹部;黑色素细胞多分布于真皮浅层,以腹部及背侧无瘰粒处多见;真皮层富含黏液腺和颗粒腺,但分布不均匀;头嵴棱部及背部瘰粒下方颗粒腺的数量多、体积大,并充满分泌物;表皮下腺体外突,其表皮细胞层数减少,形成分泌物有效通道。同时,将红瘰疣螈皮肤与其他两栖类相比可知,其以上皮肤结构特征均体现了红瘰疣螈对山区阴湿环境中陆栖生活的重要适应。     

无斑肥螈消化道五羟色胺免疫活性细胞的分布与形态学观察

用S－P免疫组织化学的方法对无斑肥塬消化道五－羟色胺（5－HTIR）免疫活性细胞的分布及形态进行了观察。结果表明,5－HTIR细胞从食道到直肠的消化道各段均有分布。其中,幽门部密度最高,十二指肠次之,直肠最低。5－HTIR细胞形态多样,有圆形、梭形、纺锤形或烧瓶形,梭形、纺锤形或烧瓶细胞有较长的胞突,有时胞突可见明显分叉。同时讨论了5－HRIR细胞的分点特点、形态与功能的关系。     

不同取样方式下大凉螈精子形态变化

精子形态在精子竞争和精子进化中具有重要地位。体内受精有尾两栖类雌性和雄性均具有复杂的泄殖腔腺体,都可能对精子形态进行进一步包装和修饰,但这些过程对精子形态特征和功能的影响目前所知甚少。本研究以体内受精的大凉螈(Liangshantriton taliangensis)为研究对象,系统观察了破碎睾丸、雄性自然排精和冲洗雌性泄殖腔3种方法所收集精子的形态变化;同时,分别利用了t检验、t’检验或U检验,探究了其定量变化。结果显示：取自精子囊和雌性泄殖腔的精子可观察到明显的颈部,而破碎睾丸取样的精子仅观察到胞质小团结构,无明显颈部结构,故推测睾丸中精子尚未成熟;精子在由睾丸到排出体外过程中顶体显著缩短,尾部所占比例显著增加(U检验或t检验,P < 0.05),而精子在由精子囊到进入雌性体内的过程中未发生形态或量度上的显著变化(U检验或t检验,P > 0.05),仅表现为顶体的进一步缩短(t检验,P < 0.05)。本研究提示,精子由睾丸到排出体外的过程中可能因其经历的修饰过程而展现出形态和量度上的差异,为精子生物学研究和精子保存提供了选择依据。     

The morphogenesis of spermathecae and spermathecal glands in Drosophila melanogaster

Sperm storage in female insects is important for reproductive success and sperm competition. In Drosophila melanogaster females, sperm viability during storage is dependent upon secretions produced by spermathecae and parovaria. Class III dermal glands are present in both structures. Spermathecal glands are initially comprised of a three-cell unit that is refined to a single secretory cell in the adult. It encapsulates an end-apparatus joining to a cuticular duct passing secretions to the spermathecal lumen. We have examined spermatheca morphogenesis using DIC and fluorescence microscopy. In agreement with a recent study, cell division ceases by 36 h after puparium formation (APF). Immunostaining of the plasma membrane at this stage demonstrates that gland cells wrap around the developing end-apparatus and each other. By 48–60 h APF, the secretory cell exhibits characteristic adult morphology of an enlarged nucleus and extracellular reservoir. A novel finding is the presence of an extracellular reservoir in the basal support cell that is continuous with the secretory cell reservoir. Some indication of early spermathecal gland formation is evident in the division of enlarged cells lying adjacent to the spermathecal lumen at 18 h APF and in cellular processes that bind clusters of cells between 24 and 30 h APF.     

Signaling during lens regeneration

The newt is one of the few organisms that is able to undergo lens regeneration as an adult. This review will examine the signaling pathways that are involved in this amazing phenomenon. In addition to outlining the current research involved in elucidating the key signaling molecules in lens regeneration, we will also highlight some of the similarities and differences between lens regeneration and development.     

A comparative proteomic analysis during urodele lens regeneration

To examine underlying mechanisms of urodele lens regeneration we have employed a proteomic analysis of 650 proteins involved in several signaling pathways. We compared expression of these proteins between the regeneration-competent dorsal iris and the regeneration-incompetent ventral iris in the newt. After a series of screenings we selected several proteins to evaluate their expression quantitatively on immunoblots. We then used these selected proteins to compare their expression between the dorsal iris of the newt and the iris of the axolotl, another urodele, which does not regenerate the lens. In the newt we find that most proteins are expressed in both dorsal and ventral iris, even though there is differential regulation. Moreover, several of these proteins are expressed in the axolotl iris as well and for some of them their expression is consistent with the regeneration potential.     

Histological study of the cloacal region and associated structures in the hedgehog tenrec Echinops telfairi

The present investigation is based on several careful dissections and on extensive series of histological sections. It has led us to the conclusion that adult male and female Echinops telfairi are in the possession of a cloaca which represents a primitive feature among mammals. This cloaca is a small, bowl-shaped pouch at the ventro-posterior end of the body. Intestinal, genital and urinary tract open into this cloaca. The opening of the intestinal tract into the cloaca is regulated by a sphincter muscle. In the female the genital and the urinary tract open into the urogenital sinus, a subcompartment of the cloaca. The cloaca of the lesser hedgehog tenrec is lined by a multilayered, non-keratinized squamous epithelium without skin glands. In a small transitory zone between the cloaca and the outer skin the epithelium changes into the keratinized, multilayered squamous epithelium of the epidermis with eccrine and holocrine glands as well as hairs. In addition, there is a distinct circular cloacal sphincter muscle, built up by cross-striated skeletal muscle tissue.

In the terminal parts of intestinal, urinary and genital tracts of male animals the following glandular structures were observed: prostate gland, Cowper's glands and strongly pigmented seminal vesicles; in female animals: the urethral and the Bartholin glands. Both males and females, in addition, possess (a) a cloacal gland, the excretory ducts of which open into the cloaca and (b) a pericloacal gland which is located in the adipose tissue on both sides of the cloaca; it presumably also opens into the cloaca.     

Histofluorescence of monoamines in newt forelimb regenerates

Summary Newt forelimb regenerates were studied at various stages of development using the histofluorescent method of Falck and Hillarp. A green formaldehyde-induced fluorescence was found in nerve fibres, large dendritic cells, skin gland cells and skin gland cell secretions. To ascertain the nature of the fluorescent material, animals were submitted to treatments with L-dopa, nialamide, benserazide and reserpine, used separately or in combination and administered before cutting off the regenerates. The modifications of the fluorescence after the various treatments confirmed the monoaminic nature of the fluorophores. Catecholaminic fibres were numerous in tissues of fast-growing stages while in dedifferentiated cell areas as well as in prochondral cell condensations and in cartilage they were completely absent. Fluorescent dendritic cells that have never been described before in regenerating limbs were observed and, from their localisation and cytological appearance, classed as promelanophores (or melanoblasts).     

云南药山自然保护区蕨类区系研究

基于馆藏标本,对云南药山自然保护区蕨类进行区系分析.结果表明:该保护区共有蕨类30科、67属、177种及10变种;属的区系地理成分可划分为10个类型11个亚型;种的区系地理成分可划分为9个类型、20个亚型及7个变型;该保护区温带区系成分占优势;与相邻地区区系成分比较发现,蕨类区系与云南药山联系的紧密程度为:轿子雪山>梅里雪山及附近地区>玉龙雪山>黄山.     

东海三疣梭子蟹纳精囊形态结构与内含物的变化

2005～2006年通过定期采样,对东海三疣梭子蟹(Portunus trituberculatus)纳精囊的形态、组织结构、内含物及相应卵巢的发育状况进行了较为深入的研究.交配前期,4～6月份,纳精囊囊壁较薄,背腹囊腔分离;随后囊壁皱缩(7～9月份),背部囊壁上皮出现分泌层;最后囊壁增厚,单层多核柱状细胞消失,腔内只含琥珀色胶状物质.交配期(10～11月份),囊腔膨大,囊壁变薄.背部近交接处出现\"凸\"或\"丁\"字型突起;相应地,腹囊腔内亦出现含角质层褶皱.精子塞是三疣梭子蟹成功交配的特征,是雌雄梭子蟹共同作用的产物,由雄性基质、雌性分泌物、精子塞不定部分和精子塞半透明部分4种物质组成;精荚仅存于雄性基质中.三疣梭子蟹的精子塞在不到2个月的时间内消失殆尽,并不能保护和滋养精子.背部突起对调控纳精囊容积起主要作用,其形成与消退与精荚运输关系密切.交配后期(12月至翌年3月),纳精囊皱缩完全;裂解完全的精荚在背腹囊腔交接处集中,最后贮藏在腹囊腔内,为后续受精做好准备.纳精囊与卵巢关系紧密,进化上可能有重要意义.纳精囊与卵巢发育相联系,可以更好地反映三疣梭子蟹的资源动态.