Assessing Genetic Differentiation in Geographic Populations of Labeo calbasu Using Allozyme Markers

The population structure of Labeo calbasu from 11 rivers belonging to the Indus, Ganges, Bhima, Mahanadi, and Godavari basins was investigated using allozyme marker systems. Seven out of 20 allozyme loci (35%) were polymorphic (P < 0.99). Both probability and score tests indicated significant deviation of genotype proportions from Hardy–Weinberg expectations at two loci, XDH* (Mahanadi, Bhima, and Godavari) and G6PDH* (Mahanadi). A pairwise genetic homogeneity test and F _ST values indicated a low-to-moderate level (0.0515) of genetic structuring in the wild population of L. calbasu. AMOVA analysis also indicated moderate differentiation among the samples from different river basins. Analysis for genetic bottleneck was performed under the infinite allele model. The study revealed nine genetic stocks of L. calbasu from the natural population across Indian rivers. Evidence of genetic bottlenecks in some rivers was also revealed.     

鲤科鱼蓝黑鲮微卫星位点的种间扩增(英文)

本研究使用105对微卫星引物对7种鲤科鱼类进行跨越种间PCR扩增,共得到14个多态性微卫星位点.其中9个扩增效果较好的位点用于分析来自帕吉勒提河(Bhagirathi, n=20)和戈达瓦里河(Godavari, n=25)的蓝黑鲮(Labeo calbasu)样品的遗传多样性.结果显示,前者在每个位点的平均等位基因数为7.33,而后者为8 1,期望杂合度介于0.795(Bhagirathi)和0.801(Godavari)之间;4个位点MFW11* (Godavari)、R1*(Godavari)、R3* (Bhagirathi) 和 Lr38*(Bhagirathi和Godavari)都表现出明显的杂合子缺失和哈迪温伯格平衡偏离;而任意两位点间都未观测到连锁不平衡现象;位点R3*极可能存在无效等位基因.上述结果表明这些多态性微卫星位点作为共显性标记在蓝黑鲮群体遗传学研究中有着较好的应用前景.     

使用多态异型酶标记物估计野鲮的遗传变异性

本文首次分析了野鲮鱼 (Labeodyocheilus)等位酶的变异情况。通过对 17个酶系统的研究 ,发现 2 8个可以稳定检测的位点 ,其中 8个位点具有多态性。使用这 8个等位酶位点 ,分析了取自不同河流 ,即Satluj、Yamuna和Tons河的样本的遗传多样性情况。结果显示 ,不同样本间存在显著的遗传异质性 ,各位点的表观杂合度介于 0 0 392 (Yamuna河 )与 0 0 4 87(Tons河 )之间。因此 ,本研究所筛选出的多态性等位酶位点为研究该野鲮鱼的种群遗传结构奠定了基础     

Plasmid characterization and pulsed-field electrophoretic analysis demonstrate that ampicillin-resistant strains of Salmonella enteritidis phage type 6a are derived from Salm. enteritidis phage type 4

Plasmid incompatibility studies have demonstrated that strains of Salmonella enteritidis phage type (PT) 6a resistant to ampicillin possess a 36 megadalton incompatibility group (Inc) X plasmid coding for resistance to ampicillin which is capable of converting strains of Salm. enteritidis belonging to PTs 1 and 4 to PT 6a, and PT 8 to PT 13. However, pulsed-field gel electrophoresis (PFGE) has demonstrated that all clinical isolates of PT 6a have a characteristic Xba I pulsed-field profile which is distinct from that of PT 1 and which can only be differentiated from that of PT 4 by the presence of plasmid-associated fragments of less than 45 kb. It is concluded that ampicillin-resistant strains of Salm. enteritidis PT 6a are derived from strains of Salm. enteritidis PT 4 by acquisition of an Inc X ampicillin resistance plasmid.     

Evaluation of Genetic Variation in the Clown Knifefish, Chitala chitala, Using Allozymes, RAPD, and Microsatellites

Twenty-seven enzyme systems, six random amplified polymorphic DNA (RAPD) primers, and two microsatellite loci were tested to determine intraspecific divergence in the natural population of the endangered Indian featherback fish, Chitala chitala, for the first time. The 262 samples of C. chitala were collected from six riverine locations in India: the Satluj, Ganga (Ghagra, Bhagirathi, and Brahmaputra), Mahanadi, and Narmada river systems. The analysis revealed population subdivisions, with an F_ST value from 0.1235 (95% confidence 0.0868–0.1621) for RAPD and a combined F_ST of 0.0344 (95% confidence 0.0340–0.0350) for microsatellite loci. An analysis of 38 allozyme loci did not reveal any polymorphism in the samples from any of the riverine localities; a possible explanation for this could be that the ancestors of Chitala could have faced a population reduction in prehistoric periods, as low allozyme variation is also reported for other species of Chitala from south Asia.     

Fine needle aspiration cytology of bursal cyst

OBJECTIVE: To evaluate the cytomorphology of bursal cyst and assess the efficacy of aspiration cytology in its diagnosis and treatment. STUDY DESIGN: Nineteen cases of bursal cyst seen over four years were studied. Material was obtained by fine needle aspiration. The smears were stained with May-Grünwald-Giemsa stain and hematoxylin and eosin. RESULTS: Eight cysts were in the popliteal fossa, 4 on the elbow, 3 on the knee, 2 on the shoulder and 2 in the calf. Gelatinous material was aspirated in all the cases. In some cases the cyst collapsed after aspiration. The key diagnostic features were hypocellular smears in a mucoid background. Histiocytelike (synovial) cells were seen lying in all cases and as pseudopapillary structures in two. CONCLUSION: The presence of a cyst at a classic location with aspiration of gelatinous material and the presence of singly occurring histiocytelike cells in a mucoid background in smears is diagnostic of bursal cyst. The procedure is therapeutic in some cases.