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The difference in fleece type is the distinguishing trait between the two types of alpacas (Vicugna pacos), Huacaya and Suri. The Suri fleece type has been found to be inherited dominantly over the Huacaya type, resulting in offspring with the Suri phenotype. The aim of our study was to map genomic regions associated with the two different fleece types. In this study, 91 alpacas (54 Huacayas and 37 Suris) from Germany and Switzerland were genotyped using the 76k alpaca SNP array. Only 59k chromosome‐localised markers map to the alpaca reference assembly VicPac3.1, and after quality control 49 866 SNPs, were retained for population structure assessment and to conduct a genome‐wide association study. Both principal component and neighbour‐joining tree analysis showed that the two fleece‐type cohorts overlapped rather than forming two distinct clusters. Genome‐wide significantly associated markers were observed in the scaffold region of chromosome 16 (NW_021964192.1), which contains a cluster of keratin genes. A haplotype predominantly found in Suri alpacas has been identified which supports dominant inheritance. Variant filtering of nine whole‐genome sequenced alpacas from both fleece types in the critical interval of 0.4 Mb did not reveal perfect segregation of either fleece type for specific variants. To our knowledge, this is the first study to use the recently developed species‐specific SNP array to identify genomic regions associated with differences in fleece type in alpacas. There are still some limitations, such as the preliminary status of the reference assembly and the incomplete annotation of the alpaca genome. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify the molecular genetic origin underlying the I variant of αs1-casein and to develop a DNA-based test for this polymorphism as a tool for genetic analyses independent of milk sample testing. All coding exons and flanking regions of the α s1 -casein gene were sequenced in DNA samples from cattle of known α s1 -casein genotypes ( BI, CI, II, CC), determined by isoelectric focusing of milk samples. A nucleotide substitution (A>T) in exon 11 (g.19836A>T) leads to the exchange of Glu with Asp at amino acid position 84 of the mature protein (p.Glu84Asp) and perfectly co-segregated with the presence of the αs1-casein I variant in the milk of the analysed animals. Genotyping of a total of 680 DNA samples from 31 Bos taurus and Bos indicus cattle breeds and from Bos grunniens, Bison bison and Bison bonasus by restriction fragment length polymorphism analysis revealed the occurrence of Asp at position 84 at low frequencies in Bos taurus and Bos indicus breeds and established its origin from the αs1-casein C variant (p.Glu192Gly). Ten different intragenic haplotypes in the gene region from intron 8 to intron 12 were observed by sequencing, of which two occurred in Bison bison and one in Bison bonasus only. Using available casein gene complex information, an association of Asp at position 84 to β-casein A2 and κ-casein B was shown in the Bos indicus breed Banyo Gudali . Taken together, we can postulate that the αs1-casein variant I is caused by a non-synonymous nucleotide substitution in exon 11 of the gene and that it originated within Bos indicus and spread to Bos taurus subsequently. [ABSTRACT FROM AUTHOR]

Microcephaly is a rare neurodevelopmental disorder characterized by reduced skull circumference and brain volume that occurs sporadically in farm animals. We investigated an early-onset neurodegenerative disorder observed in seven lambs of purebred Kerry Hill sheep. Clinical signs included inability to stand or severe ataxia, convulsions, and early death. Diagnostic imaging and brain necropsy confirmed microcephaly. The pedigree of the lambs suggested monogenic autosomal recessive inheritance. We sequenced the genome of one affected lamb, and comparison with 115 control genomes revealed a single private protein-changing variant. This frameshift variant, MFSD2A: c.285dupA, p.(Asp96fs*9), represents a 1-bp duplication predicted to truncate 80% of the open reading frame. MFSD2A is a transmembrane protein that is essential for maintaining blood-brain barrier homeostasis and plays a key role in regulating brain lipogenesis. Human MFSD2A pathogenic variants are associated with a neurodevelopmental disorder with progressive microcephaly, spasticity, and brain imaging abnormalities (NEDMISBA, OMIM 616486). Here we present evidence for the occurrence of a recessively inherited form of microcephaly in sheep due to a loss-of-function variant in MFSD2A (OMIA 002371-9940). To the best of our knowledge, this is the first report of a spontaneous MFSD2A variant in domestic animals., (© 2023 Stichting International Foundation for Animal Genetics.)