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太白山溪鲵形态特征测量与分析研究 总被引:1,自引:0,他引:1
《基因组学与应用生物学》2017,(2)
对太白山溪鲵模式产地进行考察,于陕西周至县厚畛子镇和板房子乡共采得标本28尾。基于28号标本的形态学研究,对太白山溪鲵的形态性状进行测量比较。结果表明,太白山溪鲵头长/头宽≥1.2,头体长/尾长≥1.1,头体长/头长≥4.0。雌雄成体各性状间差异不显著(p0.05),但头长头宽,头体长尾长,鼻间距吻长眼间距眼径,后肢长前肢长,尾高尾宽。体重与全长(包括其他共线性性状)、头宽呈极显著的正相关关系,吻长与体重呈显著的负相关关系,吻长与头长不相关。 相似文献
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大鲵(Andriasdavidianus)系国家二级保护野生动物。笔者于1993年夏、秋两季,在安徽省黄山市祁门县凫峰乡和休宁县流口乡收集到105尾大鲵活体,体重70~4450g。饲养在人工建造的大鲵饲养场内,开展人工繁殖研究。现将自野外收集时测得的大鲵身体各部位数据分析结果报道于后。1 测量的数据(1)体重(g):大鲵身体离开水后10分钟左右测得;(2)全长(cm):吻端至尾尖长度;(3)头长(cm):吻端至左右颈褶中间点长度;(4)头宽(cm):头最宽处长度;(5)尾长(cm):肛孔后缘至尾尖长度;(6)前肢长(cm):前肢基部至指尖长度;(7)后肢长(c… 相似文献
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我国的大鲵 总被引:2,自引:0,他引:2
形态特征大鲵Megalobairachus davidianus(Blanchard)俗称娃娃鱼、鲵鱼、(鱼帝)鱼.全长一般一米左右,大的可达2米,重达四、五十斤,为我国特产的一种大型两栖动物.头宽而扁,眼极小,位于头背面.口裂大,上下颌具有大小相似的细齿.躯干粗而扁,体侧腋胯间有纵行皮肤褶.四肢短壮,前肢四指,后肢五趾.尾长而侧扁.皮肤一般光滑,背面棕褐色,具有不规则的深色斑;腹面浅褐色或灰白色.随环境不同体色深浅有变化.本种在分类上隶属有尾目、隐鳃鲵科.该科计有2属4种,亚洲东部和北美各有一属.中国大鲵与日本大鲵形态特征极为相近,从前被视为一个种,即日本大鲵.现在多数学者主张分为两个独立的种.其主要理由是我国大鲵头及躯干部的每个疣粒是由两个紧密成对排列的小疣组成.日本大鲵,疣是单个 相似文献
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龙洞山溪鲵精子的超微结构 总被引:5,自引:0,他引:5
应用透射电镜和扫描电镜对龙洞山溪鲵(Batrachuperuslongdongensis)精子的超微结构进行观察和研究,探讨山溪鲵属以及小鲵科物种精子的结构特征,并探讨有尾两栖类精子结构特征的演化及其与生殖进化的关系。结果表明:1)龙洞山溪鲵的精子具小鲵科物种精子的共同特征,即精子无顶体钩,顶体呈三叶草状,尾部无线粒体,轴纤维粗大呈圆柱状等特征;2)龙洞山溪鲵精子核脊的形态结构与小鲵科其它属物种以及有尾类其它科物种精子的核脊存在明显的差别,由此可见核脊形态结构具有属或种的特异性。此外,与已有报道的有尾两栖类物种精子的结构特征进行分析比较表明:1)有尾类精子特征的分化与其受精方式的变化是一致的;2)精子结构特征支持隐鳃鲵超科为单系的推测 相似文献
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西藏山溪鲵精子的形态 总被引:4,自引:2,他引:2
在光学显微镜下观察和测量了西藏山溪鲵 (Batrachuperustibetanus)精子 ,结果表明 ,该物种精子具有小鲵科科精子的共同特征 :由头、颈和尾组成。头部细直 ,颈部短而不显 ,尾部长曲 ;波动膜螺旋盘绕尾部轴棒 ,轴丝游离 ;顶体包括顶体鞘和穿孔器 ;颈部短。西藏山溪鲵精子种的特异性主要表现在量度方面 :其全长为 (2 89. 85± 1 3 0 2 ) μm ,顶体长为 (1 7. 96± 3. 69) μm ,头长为 (90 . 84± 8 .3 3 ) μm ,尾长 (1 81 .0 6±1 1. 5 3 ) μm ,头宽 (2. 75± 0. 3 7) μm ,其头部在已知精子形态的小鲵科物种中最宽。本文为该科物种的生态适应进化和系统学研究提供精子形态学依据。 相似文献
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原唇柱苣苔属(Chirita Buch.-Ham. ex D. Don)为一个人为界定的属, 2011年在分子系统学研究的基础上对该属及其近缘属开展了系统发育重建工作,其中绝大部分的原唇柱苣苔属唇柱苣苔组(Sect. Gibbosaccus C. B. Clark)的物种被并入了广义报春苣苔属(Primulina Hance)。然而,由于历史原因和早期经典分类学在研究方法上的局限性以及对现报春苣苔属部分物种的营养器官与生殖器官的认知不够,该属下一些物种的分类仍存在一些问题,亟待深入研究。比如,在对中国和越南分布的苦苣苔科植物开展研究的过程中,作者发现两个报春苣苔属的物种——广布于中国西南和华南直至中南半岛中部的钟冠报春苣苔[Primulina swinglei(Merr.)Mich. Möller & A. Weber]命名人和原被认为是中国与广西特有种的疏花报春苣苔[P. laxiflora(W. T. Wang)Yin. Z. Wang]之间的鉴定存在分类学问题,需要进一步厘清两者之间的关系。该文对这两个物种进行了形态比较,同时通过对这两种植物的原始描述对比、植物标本检查、栽培观察以及野外实地观察,确定疏花报春苣苔是钟冠报春苣苔的异名。此外,还明确了钟冠报春苣苔的后选指定模式标本。 相似文献
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Intraperitoneal administration of 500 mg/kg and 625 mg/kg doses of the germ cell mutagen, ethyl methanesulphonate (EMS) in
5 consecutive days to the house rat,Rattus rattus
caused a dose-dependent reduction in its body weight, cauda epididymides weight, concentration, motility and percentage of
live spermatozoa with simultaneous increase in the percentage of their abnormal forms. Compared to 0·65% spermatozoa with
abnormal heads in the cauda epididymidis of untreated control rats, 24·86% and 65·72% such spermatozoa were observed in rats
on day 14 post treatment with 500 mg/kg and 625 mg/kg doses of EMS respectively. On day 28 post treatment corresponding values
for abnormal spermatozoa were 16·21% and 14·32%. Similarly, spermatozoa with abnormal flagella increased from 0.78% in control
rats to 9·25% and 5·75% on day 14 post treatment of 500 and 625 mg/kg doses of EMS respectively and declined to 2·91% and
2·40% on day 28 post treatment. Abnormality in the sperm head was mainly due to acrosomelessness and in the flagellum due
to bending at proximal region. However, the main effect of EMS was the development of spermatozoa without or deformed acrosomes
which may impair the fertility of rats. Analysis of various stages of differentiation of spermatozoa inthe testis revealed
that population of preleptotene and pachytene spermatocytes and of round spermatids showed a gradual decline which became
significantly less than controls on day 28 of EMS treatment. Occurrence of abnormal heads of testicular spermatids indicated
that the sperm head abnormalities originated in the testis during late spermiogenesis. 相似文献
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A thermophilic fungus Thermomyces lanuginous strain IISc 91, secreted one form each of α-amylase and glucoamylase during growth.
Both enzymes were purified to homogeneity by ion-exchange and gel-filtration chromatography and obtained in mg quantities.
α-Amylase was considered to be a dimeric protein of ∼ 42 kDa and contained 5% (by mass) carbohydrate. It was maximally active
at pH 5.6 and at 65°C. It had an activation energy of 44 kJ mol-1. The apparent Km for soluble starch was 2.5 mg ml-1. The enzyme produced exceptionally high levels of maltose from raw potato starch. At 50°C, the enzyme was stable for > 7h.
At 65°C, α-amylase was nearly 8-times more stable in the presence of calcium. Addition of calcium increaed the melting temperature
of α-amylase from 66°C to 73°C. Upon incubation at 94°C, α-amylase was progressively and irreversibly inactivated, and converted
into an inactive 72 kDa trimeric species.
Glucoamylase was a monomeric glycoprotein of ∼ 45 kDa with a carbohydrate content of 11% (by mass). It effected up to 76%
conversion of starch in 24 h producing glucose as the sole product. Its apparent Km for soluble starch was 0.04 mg ml-1 and Vmax was 660 Mmol glucose min-1 mg protein-1. It also hydrolyzed maltose. Its activity on maltooligosaccharides increased with the chain length of the substrates. Glucoamylase
was stable at 60°C for over 7h. Its activation energy was 61 kJ mol-1 Glucoamylase did not show synergistic effect with α-amylase. The properties of α-amylase and glucoamylase of Thermomyces
lanuginosus strain IISc 91 suggest their usefulness in the commercial production of maltose and glucose syrups. 相似文献
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Employing the superimposition technique of electron-microscopic immunocytochemistry ultrastructural heterogeneity of the mammotropes
in the pituitary gland of the European ferret,Mustela putorius furo,was studied. On the basis of the size of their secretory granules, the mammotropes were classified into three subtypes, type-I,
type-II and type-Ill, which may correspond to different developmental or physiological states of a single cell type. Simultaneous
study of mammotropes and somatotropes in several pairs of serial semithin sections demonstrated the occasional occurrence
of bihormonal somatomammotropes /mammosomatotropes which may represent a transitional stage of the progenitor stem-somatotrope
during its differentiation into mammotrope; alternatively it may be a functional intermediate during the cross-transformation
of somatotrope into mammotrope or
vice versa. 相似文献
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The dual acting α, β-blockers have an important place in the management of hypertension. Molecular dynamics simulations have
been carried out on all stereoisomers of seven dual acting α, β-blockers namely adimolol, amosulalol, bucindolol, carvedilol,
labetalol, medroxalol and primidolol. Three families of conformations have been identified for the group of compounds. The
pharmacophores for α and β-activity have been constructed for two of these families. 相似文献
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DNA vaccination has proved to be a generally applicable technology in various preclinical animal models of infectious and noninfectious disease and several DNA vaccines have now entered phase I human clinical trials. It is too early to predict the effectiveness of DNA vaccines in humans and whether improved formulations of DNA vaccines will be required but several lines of investigation have suggested ways in which DNA vaccines may be improved, such as increases in expession, facilitation of DNA targeting or uptake, and enhancement of immune responses. 相似文献
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Cell biology depends on the interactions of macromolecules, such as protein—DNA, protein—protein or protein—nucleotide interactions. GTP-binding proteins are no exception to the rule. They regulate cellular processes as diverse as protein biosynthesis and intracellular membrane trafficking. Recently, a large number of genes encoding GTP-binding proteins and the proteins that interact witht these molecular switches have been cloned and expressed. The 3D structures of some of these have also been elucidated 相似文献
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Two yolk proteins (YP1 and YP2) from the ovaries of Indian major carp, Labeo rohita were isolated by gel filtration and partially
characterized by the use of hydroxyapatite ultrogel column in conjunction with native PAGE. On native PAGE YP1 gave a single
protein band, whereas YP2 of gel filtration revealed the contamination of YP1, which was removed by adsorption chromatography
on hydroxyapatite ultrogel and then the YP2 was the purified one as judged by electrophoresis. Both YP1 and YP2 also stained
for lipid and contained alkalilabile phosphorus. Therefore, both yolk proteins were lipophosphoprotein. The molecular weights
of YP1 and YP2 were 620 kDa and 225 kDa respectively as determined by gel filtration on Sepharose 4B. When YP1 and YP2 were
compared in relation to some physicochemical characteristics with yolk proteins of other oviparous vertebrates including fish,
they were lipovitellin like.
Antiserum to YP2 crossreacted with YP2 and vitellogenin suggesting that YP2 was the cleaved product of vitellogenin. Anti-YP2
antiserum was not crossreacted with native YP1, whereas reduced and/or denatured YP1 was crossreacted indicating the presence
of antigenic determinants in the inner core region of YP1 polypeptide. 相似文献
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David M Prescott 《Current opinion in genetics & development》1997,7(6):807-813
Three hypotheses on the evolutionary/molecular origin of internal eliminated segments (IESs) in the germline of hypotrichous ciliates are discussed in the context of the high rate of mutation accumulation in IESs, shifting of IESs during speciation, and evolutionary scrambling of segments within some hypotrich germline genes. Developmental excision of IESs from the germline in Paramecium suggests that the parental macronucleus may provide nucleic acid sequence information to guide excision of IESs and splicing of macronuclear-destined sequences. In ciliates of the oxytrichid/stylonychid group, such a mechanism could explain the precision of excision of IESs and gene unscrambling. Recently initiated molecular/genetic studies may eventually clarify the role of the parental macronucleus in IES excision and gene unscrambling as well as the molecular mechanisms of these events. 相似文献
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Plant regeneration from mesophyll protoplasts of pepper,Capsicum annuum
L. cv. California Wonder has been demonstrated via shoot organogenesis. Protoplasts isolated from fully expanded leaves of
3-week-old axenic shoots when cultured in TM medium supplemented with 1 mg l
−1
NAA, 1 mg l
−1
2,4-D, 0 5 mg l
−1
BAP (CM 1) resulted in divisions with a frequency ranging from 20–25 %. Antioxidant ascorbic acid and polyvinylpyrrolidone
(PVP) in the medium and incubation in the dark helped overcome browning of protoplasts. Microcalli and macrocalli were formed
in TM medium containing 2 mg l
−1
NAA and 0.5 mg l
−1
BAP (CM II) and MS gelled medium containing 2 mg 1
−1
NAA and 0 5 mg 1
−1
BAP (CM III), respectively. Regeneration of plantlets was possible via caulogenesis. Microshoots, 2–5 percallus appeared on
MS gelled medium enriched with 0.5 mg l
−1
IAA, 2mg l
−1
GA and l0mg l
−1
BAP (CM IVc). Rooting of microshoots was obtained on half strength gelled medium containing 1 mg l
−1
NAA and 0.5mg l
−1
BAP. Protoplasts isolated from cotyledons failed to divide and degenerated eventually. 相似文献