Variants at the ASIP locus contribute to coat color darkening in Nellore cattle.

BACKGROUND: Nellore cattle (Bos indicus) are well-known for their adaptation to warm and humid environments. Hair length and coat color may impact heat tolerance. The Nellore breed has been strongly selected for white coat, but bulls generally exhibit darker hair ranging from light grey to black on the head, neck, hump, and knees. Given the potential contribution of coat color variation to the adaptation of cattle populations to tropical and sub-tropical environments, our aim was to map positional and functional candidate genetic variants associated with darkness of hair coat (DHC) in Nellore bulls. RESULTS: We performed a genome-wide association study (GWAS) for DHC using data from 432 Nellore bulls that were genotyped for more than 777 k single nucleotide polymorphism (SNP) markers. A single major association signal was detected in the vicinity of the agouti signaling protein gene (ASIP). The analysis of whole-genome sequence (WGS) data from 21 bulls revealed functional variants that are associated with DHC, including a structural rearrangement involving ASIP (ASIP-SV1). We further characterized this structural variant using Oxford Nanopore sequencing data from 13 Australian Brahman heifers, which share ancestry with Nellore cattle; we found that this variant originates from a 1155-bp deletion followed by an insertion of a transposable element of more than 150 bp that may impact the recruitment of ASIP non-coding exons. CONCLUSIONS: Our results indicate that the variant ASIP sequence causes darker coat pigmentation on specific parts of the body, most likely through a decreased expression of ASIP and consequently an increased production of eumelanin.

Swine cysticercosis and associated risk factors in non-technified pig breeding in semi-arid region of Sergipe state, Brazil.

The aim of this study was to determine the frequency of Taenia solium anti-metacestode antibodies in slaughtered pigs in a semi-arid region of the "Alto Sertão" of Sergipe state, Brazil, and verify the risk factors associated with swine cysticercosis. For this, 230 samples of swine blood from two slaughterhouses were collected and analyzed by indirect ELISA. The pigs came from five non-technical properties in the semi-arid region of the Alto Sertão of Sergipe state. Searches for cysts in the skeletal muscles of the pigs were performed during slaughter. In addition, an epidemiological questionnaire was applied to the pigs' original properties to determine risk factors. Besides that, the official health services database was evaluated for confirmed cases of neurocysticercosis and taeniasis in humans in the last 5 years, living in the studied region. Seropositivity in pigs was 12.6%, with no significant difference between males and females. No cysts were found in the carcasses of the slaughtered pigs. A positive association was found for properties that discharge domestic sewage into the environment, in river or streams, increasing the risk of positivity by 5.72 times. When analyzing the database of official agencies, there were no records of cases of neurocysticercosis or taeniasis in the resident population in the last 5 years. However, there were frequent cases of idiopathic epilepsy. The results demonstrate that study area is endemic for swine cysticercosis and serves as a warning of the possibility of the occurrence of the taeniasis-cysticercosis complex.