712 www.bsmiab.org/jabet Mony et al., J Adv Biotechnol Exp Ther. 2022 Sep; 5(3): 712-720 Validation study of c.746A>G SNP of BMPR1B gene associated with litter size in sheep genetic resources of Bangladesh Sabrina Islam Mony 1 , T. M. Maruf 1 , Nure Hasni Desha 2 , Mohammad Hasanuzzaman Pabitra 1 , Sadek Ahmed 2 , Md. Munir Hossain 1 , Mohammad Shamsul Alam Bhuiyan 1,* 1 Department of Animal Breeding and Genetics, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh 2 Goat and Sheep Production Research Division, Bangladesh Livestock Research Institute, Savar, Dhaka-1341, Bangladesh ABSTRACT The bone morphogenetic protein receptor type 1B (BMPR1B) gene is one of the major fecundity genes that have been investigated in different sheep populations worldwide for its association with prolificacy traits. The present study was performed to validate the association of c.746A>G SNP of BMPR1B gene with litter size trait in different sheep populations of Bangladesh. A total of 192 blood samples were collected from ewes of both farmers’ and institutional flocks comprising sheep populations of Jamuna River Basin (JRB), Barendra (BAT), Coastal (COR), Garole (GAR) and Muzaffarnagari (MUZ). Genotyping of the individuals was performed using PCR-RFLP method and single marker association analysis was carried out to evaluate the relationships between resultant genotypes and litter size trait. The prolificacy attributed homozygous FecB BB genotype frequencies were 66, 50 and 55%, respectively in JRB, BAT and GAR populations whereas it was only 0-2% in MUZ and COR populations. Association analysis revealed highly significant (P<0.001) association of litter size trait with genotypes and populations. The mean litter sizes of JRB, BAT, GAR, COR and MUZ were 2.17±0.15, 1.88±0.07 1.90±0.10, 1.12±0.03 and 1.02±0.02, respectively. The prolific JRB, BAT, and GAR ewes produced 0.67 to 0.83 more lambs per lambing than their wild type FecB ++ counterparts. Thus, this study validated the potential contribution of the investigated c.746A>G SNP that could be applied in marker assisted selection (MAS) program for identifying high prolific ewes in order to improve litter size trait at the population level. INTRODUCTION Indigenous sheep is one of the important livestock species in Bangladesh primarily used for mutton production. The total heads of sheep in Bangladesh are about 3.61 million [1] which are mainly concentrated in some agro-ecological zones namely Coastal regions (COR), Barind tracts (BAT) and Jamuna River basin (JRB) areas [2]. Garole (GAR) is a world-famous dwarf type sheep breed available in and around the Sundarban delta region (SDR). Sheep genetic resources of Bangladesh are comprised of mostly non-descript indigenous types along with a small proportion of exotic pure breed and crossbreds [3,4]. Indigenous sheep have greater adaptability under hot and humid climatic conditions with better disease resistance capability. Moreover, the capability of bi-annual lambing with multiple birth and withstand ability to utilize low quality roughage make them a suitable ruminant for small and marginal farmers [5,6]. On the other hand, notable differences were observed among the individuals of within and between sheep populations of Bangladesh for production, reproduction and morphometric traits. For example, litter size of COR sheep was significantly lower than the sheep populations of SDR and JRB [7] . Litter size is one of the important traits of multiparous livestock species that is directly related to the economic benefits of farms. Reproductive traits such as ovulation rate and litter size are genetically influenced by major genes known as fecundity genes [8,9]. The * Corresponding author Mohammad Shamsul Alam Bhuiyan Department of Animal Breeding and Genetics, Bangladesh Agricultural University, Mymensingh, Bangladesh e-mail: msabhuiyan.abg@bau.edu.bd Academic editor Hasan-Al-Faruque, PhD University of Utah USA. Article info Received: 19 June 2022 Accepted: 05 August 2022 Published: 10 August 2022 Keywords Bangladesh; BMPR1B; Prolificacy; Sheep; SNP. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ORIGINAL ARTICLE J Adv Biotechnol Exp Ther. 2022 Sep; 5(3): 712-720 eISSN: 2616-4760, https://doi.org/10.5455/jabet.2022.d149 Published by www.bsmiab.org