Genetic diversity, introgression and relationships among West/Central African cattle breeds

Abstract

-Genetic diversity, introgression and relationships were studied in 521 individuals from 9 African Bos indicus and 3 Bos taurus cattle breeds in Cameroon and Nigeria using genotype information on 28 markers (16 microsatellite, 7 milk protein and 5 blood protein markers). The genotypes of 13 of the 16 microsatellite markers studied on three European (German Angus, German Simmental and German Yellow) and two Indian (Nelore and Ongole) breeds were used to assess the relationships between them and the African breeds. Diversity levels at microsatellite loci were higher in the zebu than in the taurine breeds and were generally similar for protein loci in the breeds in each group. Microsatellite allelic distribution displayed groups of alleles specific to the Indian zebu, African taurine and European taurine. The level of the Indian zebu genetic admixture proportions in the African zebus was higher than the African taurine and European taurine admixture proportions, and ranged from 58.1% to 74.0%. The African taurine breed, Muturu was free of Indian zebu genes while its counter Namchi was highly introgressed (30.2%). Phylogenic reconstruction and principal component analysis indicate close relationships among the zebu breeds in Cameroon and Nigeria and a large genetic divergence between the main cattle groups -African taurine, European taurine and Indian zebu, and a central position for the African zebus. The study presents the first comprehensive information on the hybrid composition of the individual cattle breeds of Cameroon and Nigeria and the genetic relationships existing among them and other breeds outside of Africa. Strong evidence supporting separate domestication events for the Bos species is also provided.

Genetic Diversity of Kedah Kelantan Cattle Breed and Its Crossbred types in Malaysia Based on Microsatellite Markers

“…Similar levels of introgression of Indian zebu genes (17 − 26.3%) in seven indigenous cattle breeds in central and southern China have been reported by Zhang [30]. Higher level of introgression of Indian zebu genes into indigenous cattle breeds from North Ethiopia (55.16 -63.78%) was reported byZerabruk[43] and among west-central African cattle breeds (58.1−74.0%) by Ibeagha-Awemu[44].…”

“…One to ten inferred clusters were performed with 20 independent runs each. Based on references [18][19][20] that suggest groups of alleles which may be used as diagnostic markers of Indian zebu, African taurine and European taurine breeds, the frequencies of these alleles at the loci were averaged to estimate of proportion of introgression from the individual cattle groups.…”

Microsatellite Analysis of Genetic Population Structure of Zebu Cattle (Bos indicus) Breeds from North-Western Region of India

“…For evolutionary close populations as in the present study, drift based (D A ) measure 32 is thought to be the most appropriate to analyze inter-breed proximity. In the past, this approach has been in greater use for intra-species (between breed) comparison in several livestock species viz., cattle; 11,12,33,34 buffalo; 35,36 Sheep; 37 and goat. 38 The magnitude of zebu and taurine divergence reflected by 100% boot strapping supported the hypothesis that the two groups diverged prior to the first appearance of domesticated cattle in Neolithic period and provided strong support for two independent domestications of cattle.…”

Across the Indian Ocean: the prehistoric movement of plants and animals

“…Broomcorn millet is known from other central Asian sites from around 2000 BC and is found in Pakistan at c. 1900 BC, Yemen at around 2000 BC, and in Sudanese Nubia by c. 1700 BC (Figure 1, left inset), while being absent from intervening regions such as Egypt and Mesopotamia . Zebu cattle may also have moved from India to Yemen and East Africa starting at this time, although this was presumably the first stage in an ongoing process of gene flow through introduced bulls which made the genetic landscape of south Arabian and African cattle one of hybridity between African taurine and Indian zebu stocks, with evidence for interbreeding most marked at the margins of the Indian Ocean (Hanotte et al 2002;Ibeagha-Awemu et al 2004). These zebu-hybrid cattle played an important role in the longterm success and southernmost spread of cattle pastoralists in eastern Africa (cf.…”