Augustin Vlaic

Identification of an intronic regulatory mutation at the buffalo αS1-casein gene that triggers the skipping of exon 6.

The characterization of casein polymorphism is an essential step in order to understand the genetic basis of milk quality in dairy ruminants. In this work, we report the identification of a regulatory mutation at the buffalo αs1-casein (CSN1S1) gene that alters the normal processing of the primary transcript. Sequencing of CSN1S1 cDNA from individuals harbouring this new variant revealed that its most distinctive feature is the loss of exon 6 that encodes eight amino acids between positions 35–42 of mature protein. In an effort to map the causal mutation, we sequenced a genomic region spanning exons 5–7 of the buffalo CSN1S1 gene. This experiment allowed us to establish that exon 6-skipping is produced by a G to C substitution at the first position of intron 6 that inactivates the donor splice site. This mutation can be typed by PCR–RFLP by using either TaaI or Bpu10I diagnostic restriction enzymes, and it has a frequency of 0.18 in Romanian buffaloes. This exon skipping phenomenon is the first one described in buffalo CSN1S1 locus.

New Insights on Water Buffalo Genomic Diversity and Post-Domestication Migration Routes From Medium Density SNP Chip Data

The domestic water buffalo is native to the Asian continent but through historical migrations and recent importations, nowadays has a worldwide distribution. The two types of water buffalo, i.e., river and swamp, display distinct morphological and behavioral traits, different karyotypes and also have different purposes and geographical distributions. River buffaloes from Pakistan, Iran, Turkey, Egypt, Romania, Bulgaria, Italy, Mozambique, Brazil and Colombia, and swamp buffaloes from China, Thailand, Philippines, Indonesia and Brazil were genotyped with a species-specific medium-density 90K SNP panel. We estimated the levels of molecular diversity and described population structure, which revealed historical relationships between populations and migration events. Three distinct gene pools were identified in pure river as well as in pure swamp buffalo populations. Genomic admixture was seen in the Philippines and in Brazil, resulting from importations of animals for breed improvement. Our results were largely consistent with previous archeological, historical and molecular-based evidence for two independent domestication events for river- and swamp-type buffaloes, which occurred in the Indo-Pakistani region and close to the China/Indochina border, respectively. Based on a geographical analysis of the distribution of diversity, our evidence also indicated that the water buffalo spread out of the domestication centers followed two major divergent migration directions: river buffaloes migrated west from the Indian sub-continent while swamp buffaloes migrated from northern Indochina via an east-south-eastern route. These data suggest that the current distribution of water buffalo diversity has been shaped by the combined effects of multiple migration events occurred at different stages of the post-domestication history of the species.

DESCRIPTION OF AN ENLARGED SELECTION NUCLEUS

The phenotypic performance of an enlarged selection nucleus of carp population from North-Western Transylvania is described in this paper. Aspects concerning the total body length, head length, maximal height, and body weight were recorded. The body length of the body is over 63 cm. The head length, important criteria in selection and index of slaughter yield recorded an average of 12.5 cm in both sexes. The index of body shape recorded an average of 3.33 by population, indicationg a long shape with linear back. The thorax perimeter recorded an average of 44.3 cm in males and 43.1 cm in female. The body weight recorded values of 4300 g in females and 4500 g in males.

Identification of two possibles new casein alleles in Romanian buffalo milk: αS1-casein BRV, β-casein CRV.

Milk proteins polymorphism was intensively studied in Italian Buffalo and other buffalo breeds due to its importance in mozzarela cheese pr oduction, being used as genetic markers for identifying cheeses autenticity. UTLIEF and PAGE of whole Italian Water Buffalo casein showed just one phenotype for αS1-CN (A), β-CN (B) and k-CN (B), respectively and three phenot ypes for αS2CN (Chianese et al., 2006). An additional β-casein variant named A was observed in Venezuelan Buffalo (Ferranti et al., 1998), but never in Itali an Buffalo or other European breeds. A silent allel e, named αS1-CN B, was recently discovered by RP-HPLC in Ital ian Buffalo (Chianese et al., 2006). Milk protein polymorphism was studied in 139 indivi uals from 3 different Romanian Buffalo populations, herds belonging to the National Geneti c Patrimony. To our knowledge milk proteins polymorphism in this breed has never been investiga ted so far. Genotyping was carried out in 20052006 from milk samples by IEF, as reported before ( Bâlteanu et al., 2007). The presence of two new possible casein alleles was observed (always togeth er and only in heterozygous form with αS1-A and β-B), with a 14% frequency in analyzed populations. They were named: αS1 casein B and β-casein C (Figure 1). The complete characterisation at the p rotein and DNA level is in progress, in order to establish the aminoacid and nucleotide substitution s. As these new casein variants appear only in Romanian Buffalo, their influence on milk quality a nd cheese yield will be investigated. They could be used as genetic markers for Romanian Buffalo ch eeses treaceability.