Genetic Variation and Relationship of Six Indian Sheep Breeds Adapted to the Northwestern Arid Zone of Rajasthan

2011 ◽  
Vol 49 (7-8) ◽  
pp. 449-457
Author(s):  
R. Arora ◽  
S. Bhatia ◽  
B. P. Mishra
Keyword(s):  
Genetic Variation ◽  
Arid Zone ◽  
Sheep Breeds ◽  
Relationship Of ◽  
Indian Sheep

Evaluation of Indian sheep breeds of arid zone under heat stress condition

2016 ◽  
Vol 141 ◽  
pp. 113-117 ◽  
Author(s):  
K. Mahesh Singh ◽  
Sanjeev Singh ◽  
Indrajit Ganguly ◽  
Anita Ganguly ◽  
Raja K. Nachiappan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Condition ◽  
Arid Zone ◽  
Sheep Breeds ◽  
Heat Stress Condition ◽  
Indian Sheep

Genetic variation and relationship of ultrasonic measures and carcass composition in Suffolk cross lambs

1996 ◽  
Vol 1996 ◽  
pp. 111-111
Author(s):  
V.C. Flamarique ◽  
R.M. Lewis ◽  
G. Simm
Keyword(s):  
Genetic Variation ◽  
Selection Criteria ◽  
Live Weight ◽  
Ultrasonic Measurement ◽  
Carcass Composition ◽  
Selection Indices ◽  
Terminal Sire ◽  
Relationship Of ◽  
The Relationship

Excess fat in lamb is regarded as an important reason for less lamb meat being purchased by consumers. This has encouraged the development and use (particularly in Terminal Sire breeds) of selection indices that can identify animals that will sire leaner progeny. These indices usually include live weight and in vivo predictors of body composition, such as an ultrasonic measurement of muscle and fat depth, as selection criteria (Simm and Dingwall, 1989). But the usefulness of such in vivo measurements as predictors of carcass composition depends on the correlation between, and the variation in, live and carcass measures. The objectives of this study were to determine the strength of the relationship between ultrasound and dissection measures of carcass composition, and the degree of genetic variation in these measures, in crossbred progeny of Suffolk rams.

scholarly journals POPULATION GENETIC CONSEQUENCES OF FEEDING HABITS IN SOME FOREST LEPIDOPTERA

Genetics ◽  
1979 ◽  
Vol 92 (3) ◽  
pp. 1005-1021
Author(s):  
Charles Mitter ◽  
Douglas J Futuyma
Keyword(s):  
Genetic Variation ◽  
Environmental Heterogeneity ◽  
Feeding Habits ◽  
Functional Relation ◽  
Allozyme Variation ◽  
Unexpected Result ◽  
Polymorphic Loci ◽  
Allozyme Loci ◽  
Race Formation ◽  
Relationship Of

ABSTRACT By surveying variation at allozyme loci in several phytophagous lepidopteran species (Geometridae), we have tested two hypotheses about the relationship of genetic variation to environmental heterogeneity: (1) that allozyme polymorphisms may exist because of associations between genotypes and "niches" (different host plants, in this instance), and (2) that the overall genetic variation of a species is correlated with environmental heterogeneity (or breadth of the species' overall ecological niche) .—Genetic differentiation among samples of oligophagous or polyphagous species taken from different host species was observed in one of three species, at only one of seven polymorphic loci. The data thus provide no evidence for pronounced genetic sub-structuring, or "host race" formation in these sexually reproducing species, although host plant-genotype associations in a parthenogenetic moth give evidence of the potential for diversifying selection.—In a comparison of allozyme variation in polyphagous ("generalized") and oligophagous ("specialized") species, heterozygosity appeared to be higher in specialized species, at all polymorphic loci but one. I t is possible that this unexpected result arises from a functional relation between breadth of diet and genetic variation.

scholarly journals Evidence for independent domestication of sheep mtDNA lineage A in India and introduction of lineage B through Arabian sea route

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ranganathan Kamalakkannan ◽  
Satish Kumar ◽  
Karippadakam Bhavana ◽  
Vandana R. Prabhu ◽  
Carolina Barros Machado ◽  
...  
Keyword(s):  
Arabian Sea ◽  
Indian Subcontinent ◽  
Domestic Sheep ◽  
Published Data ◽  
Sheep Population ◽  
Sheep Breeds ◽  
The World ◽  
History Of ◽  
Wild Sheep ◽  
Indian Sheep

AbstractIndia ranks the second in the world in terms of its sheep population with approximately 74.26 million represented by 44 well-described breeds in addition to several non-descript populations. Genetic diversity and phylogeography of Indian sheep breeds remain poorly understood, particularly for south Indian breeds. To have a comprehensive view of the domestication history of Indian sheep, we sequenced the mitochondrial DNA (mtDNA) control region (D-loop) and cytochrome b gene (CYTB) of 16 Indian domestic sheep breeds, most of them (13) from the south India. We analysed these sequences along with published data of domestic and wild sheep from different countries, including India. The haplotype diversity was relatively high in Indian sheep, which were classified into the three known mtDNA lineages, namely A, B and C. Lineage A was predominant among Indian sheep whereas lineages B and C were observed at low frequencies but C was restricted to the breeds of north and east India. The median joining network showed five major expanding haplogroups of lineage A (A1–A5). Out of which, A2, A4 and A5 were more frequent in Indian sheep in contrast to breeds from other parts of the world. Among the 27 Indian sheep breeds analysed, Mandya and Sonadi breeds were significantly different from other Indian breeds in the MDS analyses. This was explained by a very high contribution of lineage B into these two breeds. The Approximate Bayesian Computation (ABC) provided evidence for the domestication of lineage A sheep in the Indian subcontinent. Contrary to the current knowledge, we also found strong support for the introduction of lineage B into Indian subcontinent through sea route rather than from the Mongolian Plateau. The neighbour-joining tree of domestic and wild sheep revealed the close genetic relationship of Indian domestic sheep with Pakistani wild sheep O. vignei blanfordi. Based on our analyses and archaeological evidences, we suggest the Indian subcontinent as one of the domestication centres of the lineage A sheep, while lineage B sheep might have arrived into India from elsewhere via Arabian sea route. To the best of our knowledge, this is the first comprehensive study on Indian sheep where we have analysed more than 740 animals belonging to 27 sheep breeds raised in various regions of India. Our study provides insight into the understanding of the origin and migratory history of Indian sheep.

Genetic variation and distances of five Italian native sheep breeds

1990 ◽  
Vol 21 (1) ◽  
pp. 87-92 ◽  
Author(s):  
M. ZANOTTI CASATI ◽  
G. C. GANDINI ◽  
P. LEONE
Keyword(s):  
Genetic Variation ◽  
Sheep Breeds ◽  
Native Sheep

Polymorphism in Exon 17 of Diacylglycerol Acyltransferase-1{DGAT-1)Gene in Indian Sheep Breeds

2016 ◽  
Vol 22 (2) ◽  
pp. 170
Author(s):  
Rajiv Kumar ◽  
Shringarika Gupta ◽  
A.S. Meena ◽  
S.M.K. Naqvi ◽  
S. Kumar
Keyword(s):  
Diacylglycerol Acyltransferase ◽  
Sheep Breeds ◽  
Indian Sheep

RFLP analysis of mitochondrial D-loop region in Indian sheep breeds

2015 ◽  
Vol 21 (1) ◽  
pp. 13
Author(s):  
M.G. Sahare ◽  
A.D. Sawaimul ◽  
S.Z. Ali ◽  
A.R. Sirothia ◽  
S. Kumar
Keyword(s):  
Rflp Analysis ◽  
Sheep Breeds ◽  
Loop Region ◽  
D Loop ◽  
Indian Sheep

Variation in the host-parasite relationship of a crop disease

1968 ◽  
Vol 71 (1) ◽  
pp. 19-36 ◽  
Author(s):  
M. H. Arnold ◽  
S. J. Brown
Keyword(s):  
Genetic Variation ◽  
Environmental Conditions ◽  
Phage Type ◽  
Resistance Breeding ◽  
Wide Range ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Main Components ◽  
Host Parasite ◽  
Relationship Of

SummaryVariations in the host–parasite relationship of bacterial blight of cotton, caused by Xanthomonas malvacearum, E. F. Smith (Dowson), axe elucidated in terms of the three main components of variation, namely, genetic variation in the host, genetic variation in the parasite and variations in environment.Although the relative resistance shown by host varieties differed both with the culture of the pathogen used for inoculation and with the environmental conditions, over-riding patterns of host resistance could be detected, showing that certain varieties maintained their resistance over a wide range of conditions.It was found that phage type in X. malvacearum was not related to virulence. Moreover, none of the cultures of the pathogen which had been isolated from different sources, could be shown to be identical when inoculated into a range of host varieties under a range of environmental conditions. It was concluded that the pathogen showed continuous variation in virulence and that it would be difficult and of little value to attempt to define races.Some success was achieved in relating observed variations in the host–parasite relationship to easily measured components of the environment, by using multiple regression analyses. It is suggested that this might provide a means of characterizing the complex variations observed and that the host–parasite relationship could be regarded as a dynamic system, in which disease expression is a function of the interactions of environmental factors and two polygenic systems, that of the host and that of the parasite.Intrapopulation variances were also studied in the host varieties. A population which showed little variation for resistance under one set of conditions might show considerable variation in a different environment or when inoculated with a different culture. It is suggested that selection for resistance under conditions which favour the expression of variation can lead, by repeated selection and inbreeding, to the production of resistant populations which retain their resistance under conditions in which the parental stocks showed no worthwhile resistance. These conclusions are discussed in relation to problems in resistance breeding and genetics.

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