S.O. Pratap

Genetics of hyperpigmentation associated with the Fibromelanosis gene (Fm) and analysis of growth and meat quality traits in crosses of native Indian Kadaknath chickens and non-indigenous breeds

1. The study investigated the extent of hyperpigmentation (a trait fixed in native Indian Kadaknath chickens), bodyweight, carcase quality and leanness at 12 weeks of age in F1 and back-crosses of Kadaknath with White Leghorn, White Plymouth Rock and Aseel Peela chickens. 2. The objective of the study was to determine if hyperpigmentation was affected by the major gene Fibromelanosis (Fm) and to evaluate the effects of different proportions of Kadaknath genes on growth and carcase quality. 3. The pigmentation pattern of skin indicated that Fm behaved as the primary locus affecting dermal-hyperpigmentation and that the sex-linked Id locus produced an epistatic effect. 4. The results suggested that variable allelic forms of Id were acting in different crosses, which resulted in variation in melanosis of the host. However, no conclusive pattern for shank pigmentation could be explained through genotyping of the Id and Fm loci. 5. Analysis of quantitative traits indicated the positive impact of a Kadaknath genomic proportion of 50% or more on meat texture and carcase leanness. Improvement in leanness occurred in White Rock crosses but not in White Leghorn and Aseel Peela crosses. 6. Thigh-meat texture was influenced more by enhanced Kadaknath genomic proportions than the breast-meat. It was concluded that introgression of Kadaknath genomic proportion beyond 50% in a cross with meat-type chickens, irrespective of the impact Fm, brought improvement in meat quality whereas no such advantage was obtained for growth traits. 7. The beneficial impact of the Kadaknath genome on meat quality calls for further studies to identify causative genes for their selective use to improve meat quality in Kadaknath crossbred chickens.

Genetic appraisal of four Japanese quail lines using microsatellites

Genetic appraisal of four specialized lines of quails developed at CARI Izatnagar: CARI UTTAM (CU), CARI UJJWAL (CJ), CARI SWETA (CS) and CARI PEARL (CP) were carried using quail-specific microsatellites to elucidate the present genetic constitution and diversity in light of breeding history. The microsatellite genotyping data generated from 44 polymorphic loci was analysed to arrive at various population parameters like allele distribution, polymorphic information content (PIC), heterozygosity, F-statistics, genetic distance, genetic identity and phylogenetic distribution of the four lines. Population parameters derived from microsatellite analyses were indicative of ample genetic diversity existent within and between four lines and some of the diversity indices corroborated well with the breeding history of four lines. Phylogenetic study revealed faithful clustering of individuals within a population together with no outliers however, overall relationship between the four lines thatindicated that CS and CP lines were phylogenetically closer to each other and CU stood distinctly apart, did not corroborate well with the breeding and selection history but, went down well with pair wise measures of diversity such as Neis genetic distance and Neis genetic identity.

Diversity analysis in two defined strains of Japanese quails using microsatellite markers

A study was conducted to evaluate genetic differences between two diverse Japanese quail strains, CARI UTTAM (CU) and CARI PEARL (CP) possessing variant genetic background due to long term selection and breeding programmes, using six polymorphic quail specific microsatellite markers. Results revealed variable population parameters with all the measures of genetic diversity PIC, Ne, Nei index, Ho, He and Shannon index (I) showing higher values for CU as compared to CP while three important F statistic estimates: FIS, FST and FIT were lower in CU. Intra-strain variability assessed through un-rooted dendrograms exhibited distinctly different dispersal patterns. The results correlated well with the breeding histories of these flocks indicating that CU was more diverse compared to CP. It was inferred that employment of half a dozen polymorphic microsatellites though insufficient, could yet provide valuable assessment of intra and inter strain diversities in such quail strains arisen due to unique breeding histories and evolutionary force (selection).

Inheritance of plumage colour variations in a large flock of Japanese quail

1. The inheritance of various plumage colour variants and their underlying interactions were investigated in a large flock of Japanese quail maintained at CARI (India) by conducting reciprocal crosses between four breeding stocks inheriting Pharaoh, White Breasted, White and Brown plumages, followed by test crosses. 2. Based on the proportion of plumage-colour types in the progeny, putative genotypes were determined for parents and offspring for each of the crosses. 3. The White and Brown phenotypes were attributed to the Panda (S) and Roux (Br) loci respectively in agreement with contemporary quail stocks. 4. The White Breasted plumage type present in our stock was caused by a novel mutation with dominant gene action at an autosomal locus that was not allelic to either Panda or the White feather locus. 5. A recessive epistatic action of the Panda locus (S) on White Breasted (Wb) resulted in a White colour phenotype. 6. A novel phenotype, White Breasted-Brown was co-expressed with the Br and Wb loci. 7. It was concluded that breeding for customized feather colour phenotypes in Japanese quail using colour mutations was feasible and would be advantageous in order to overcome the limitations of legislation to protect wildlife in India.