P. Masina

Molecular characterization of the goat CSN1S1 01 allele

Caseins (α s1 , β, α s2 , e κ) represent about 80% of the whole protein content of ruminant milk. Each of these proteins is encoded by single copy genes ( CSN1S1 , CSN2 , CSN1S2 and CSN3 , respectively) clustered on a ∼200-kb segment of chromosome 6 (Ferretti et al. 1990; Gallagher et al. 1994) in the order: CSN1S1 , CSN2 , CSN1S2 and CSN3 (Mercier & Vilotte, 1993). Furthermore, in cattle and goat CSN1S1 and CSN2 are convergently transcribed (Leroux & Martin, 1996; Rijnkles et al. 1997) and are only 20 and 12 kb apart, respectively.

Expression of triplicated and quadruplicated α globin genes in sheep

Summary. In the sheep ααα globin gene haplotype, the three genes display from the 5′ to the 3′ end the percentage efficiencies of about 30:14:6, as indicated by the amounts of the three types of α chain produced in the ααα/ααα homozygotes. The 3′ gene in the αααα haplotype appears to have an efficiency around 1%, as suggested by analysis of one quadruple a homozygote. Moreover, the total outputs of the ααα as well as of the αααα haplotypes do not substantially differ from that of the common αα haplotype.

Restriction fragment length polymorphism in the 3′ flanking region of the rabbit β1-globin gene

By Southern blot analysis, a restriction fragment length polymorphism in the 3′ flanking region of the rabbit β1-globin gene was detected. Two alleles, characterized by 9.7- and 12.4-kb BamHI fragments and by 15.3- and 18.0-kb HindIII fragments, have been detected in a small population of White New Zealand rabbits. The long allele is the most frequent (about 70%). The simultaneous changes in the restriction patterns of the two endonucleases and the constant distance between BamHI and HindIII sites in short and long fragments suggest the possibility that the two alleles arise from a rearrangement phenomenon involving a DNA segment 2.7 kb long. In addition, the presence of the two alleles in individuals genetically unrelated to the White New Zealand breed suggests that this polymorphism is widespread.

Triplication of α-globin genes is responsible for unusual α113Leu/α113His-globin chain ratios in sheep

By investigations at the DNA and protein level, it has been shown that in sheep a previously detected, presumed quantitative allele of theIIα113His gene, displaying a reduced efficiency (called theIIα113His↓ gene), is carried by a chromosome bearing three α-globin loci. In particular, five sheep having an α113Leu/α113His-chain ratio of about 13:1 (13:1 phenotype) possessed the —Iα113Leu—IIα113Leu—/—Iα113Leu—IIα113Leu —IIIα113His↓ genotype. One sheep showing a α113Leu/α113His-chain ratio of about 3:1 (3:1 phenotype) had the —Iα113Leu—IIα113His—/—Iα113Leu—IIα113Leu —IIIα113His↓ genotype, while one sheep having a chain ratio of about 6:1 (6:1 phenotype) carried the —Iα113Leu—IIα113Leu—IIα113His↓—/—Iα113Leu—IIα113Leu —IIIα113His↓ genotype. Nineteen sheep, displaying the common phenotypes, all possessed the αα/αα gene arrangement. Furthermore, the possible location of the gene with reduced efficiency and the expression of the three genes in the triple α-globin loci chromosome are discussed.

Differences in the number of embryonic and pseudo-β-globin genes between HbA and HbB sheep

DNA samples obtained from 8 goats, 1 moufflon, and 84 sheep with HbA, HbAB, and HbB belonging to different breeds were digested withBamHI,EcoRI,HindIII andPstI and probed with the 5′ end of the goat εIV- and ψβZ-globin genes. Sheep homozygous for HbA show a different restriction pattern than sheep homozygous for HbB with each of these endonucleases. The main differences is that HbB sheep lack the εH and ψβX genes. These results, in addition to those previously obtained using a probe specific for β-globin genes, suggest that HbB sheep probably lack the preadult four-gene set. The DNAs from moufflon and sheep homozygous for HbA show indistinguishable restriction patterns. Furthermore, a number of restriction fragment length polymorphisms (RFLPs) are detected in the εIV and ωβZ DNA regions, and oneHindIII RFLP in the εVI DNA region.

Immunogenetics of a macroglobulin allotype in cattle.

Several serum antigens (allotypes) have been by now identified in cattle. These include markers of both light and heavy IgG chains (Blakeslee, Butler & Stone, 1971; Blakeslee, Rapacz & Butler, 1971), of macroglobulin (Iannelli, Masina & Zacchi, 1968; Rapacz, Korda & Stone, 1968; Iannelli, 1969) and low-density lipoprotein molecules (Iannelli et al. 1977). In addition to these, two more allotypic specificities are known, carried on as yet unidentified classes of molecules: Eel (Rapacz et al. 1975), which is an antigenic determinant derived from lysed erythrocytes, and wbAl (Iannelli, 1974), common to both cattle and water buffalo, and detected by allo-immune antibodies against water buffalo serum. Where determinants carried by macroglobulin molecules are concerned, those already described are Mel (Rapacz et al. 1968) and McAl or as it was initially named Ci(a) (Iannelli et al. 1968). The present paper describes a third macroglobulin allotype (McA2) and its genetic and immunochemical relationship to the above mentioned McAl allotype.

Evidence for 15 genetically determined electrophoretic variants of transcobalamin II in rabbit serum

By starch gel electrophoresis and autoradiography two classes of vitamin B12 binding proteins were detected in rabbit serum. By analogy to the nomenclature used in man, the two classes of proteins were named “transcobalamin I” (TCI) and “transcobalamin II” (TCII). Fifteen TCII phenotypes were observed, and family data indicated that they are controlled by five allelic codominant genes. The possibility that the five genes arise from the action of at least two polymorphic and closely linked structural loci is discussed.