The structure of goat hemoglobins. V. A fourth beta chain variant (beta-D-Malta; 69 Asp is replaced by Gly) with decreased oxygen affinity and occurring at a high frequency in Malta

Restriction fragment length polymorphism of the caprine beta-globin gene cluster associated with the Hb beta-globin variants in Norwegian dairy goats

Restriction fragment length polymorphism (RFLP) analysis was used to characterize the beta-globin cluster in Norwegian dairy goats. In 122 individuals, different RFLP patterns were detected after BglII and PstI digestion and hybridization with a caprine beta-globin probe. The location of the polymorphic BglII and PstI sites were determined. The different RFLPs were in linkage disequilibrium with each other and with the beta-globin locus as studied at the protein level. A preferential association between certain RFLP haplotypes and beta-globin variants was observed. Polymorphic DNA fragments in the epsilon-globin genes were detected after MspI digestion and hybridization with a caprine epsilon-probe, and eight different band patterns were observed. Correlation between different MspI haplotypes and the beta-globin variants was determined.

Search for genetic variation in the blood of Norwegian dairy goats reveals a new polymorphism at the Hb beta A locus

A total of 150 blood samples tested for serum albumin and transferrin and for red cell carbonic anhydrase, phosphoglucomutase, phosphogluconate dehydrogenase, phosphohexose isomerase, nucleoside phosphorylase, acid phosphatase, 'X'-protein and potassium concentration only showed variation at the 'X' protein and nucleoside phosphorylase loci. Isoelectric focusing over pH range 6-8 showed 145 samples to be of haemoglobin type A and 5 type AD. The haemoglobin A type was resolved into further types by separation over pH 6.9-7.5 in Immobiline polyacrylamide gels. A 2- or 4-band pattern was present in 136 of the samples; a genetic hypothesis based on four or more different haemoglobin A variants is proposed. 14 samples had a 3-, 5- or 6-band pattern. It is assumed that these are heterozygous for a variant of the II alpha gene.

An investigation of five genetic loci controlling polymorphic variants in the red cells of goats

Results of a joint study carried out in South Africa and England to search for new genetic markers in the blood of goats are presented. Haemoglobin (Hb) phenotypes were reinvestigated with the technique of isoelectric focusing; frequencies in different goat breeds are given. Anaemic Hb type A, AB and B goats all produced a Hb C with an identical electrophoretic pattern. All goats tested had identical carbonic anhydrase (CA) types, but showed polymorphism of 'X' protein. Preliminary results indicated that nucleoside phosphorylase (NP) may be polymorphic.

Structure and function of sheep hemoglobin Chios: A novel allele at the HBBB locus with two Lys-->Arg substitutions at positions beta66(E10) and beta144(HC1)

A novel hemoglobin variant was observed in pure sheep (Ovis aries) breeds of the island of Chios (Greece), Egypt and Hungary. This silent variant was identified by gel electrophoresis and RP-HPLC of dissociated globin chains. Two Arg for Lys substitutions were detected, by means of MALDI TOF electrospray mass spectrometric analysis for the intact globins, at positions beta66(E10) and beta144(HC1) of a globin chain having the sequence of the beta(B) chain. Sequencing of the beta-globin gene confirmed the variant gene as being an allele of the HBBB locus having the AAG-->AGG and the AAA-->AGA mutations at codons 66 and 144, respectively, both corresponding to the Lys-->Arg substitution. The intrinsic oxygen affinity of the variant Hb (logP(50)=0.79 at pH 7.0) was found to be intermediate between that of the sheep Hb B (logP(50)=0.92) and that of Cypriot mouflon (O. a. ophion) Hb (logP(50)=0.53), the latter having only the Lys-->Arg change at beta144, whereas nearly no differences were observed in the presence of the Cl(-) physiological effector. Result supports the indication that Arg at beta144 enhances the role of the ligand in decreasing oxygen affinity, this effect being partially counteracted when Arg is at beta66. Data also shows that the Lys-->Arg change at beta66 is responsible for 1.49 fold reduction in the intrinsic oxygen affinity. This hitherto undescribed variant increases to seven the number of alleles at the sheep HBBB locus. Following the nomenclature used for human Hb variants, the new allele was termed as the Hb Chios or [beta(B)66(E10) Lys-->Arg, 144(HC1)Lys-->Arg], whereas the proposed genetic nomenclature of the locus is HBBK.

The alpha chains of goat hemoglobins: old and new variants in native Apulian breeds

Blood samples were collected from 324 goats belonging to the native Apulian breeds Garganica and Jonica; 60 Alpine goats were also sampled to serve as a comparison. Hemoglobin phenotypes were analyzed with isoelectric focusing in a pH range of 6.7-7.7. Heterogeneity of globin chains was evidenced both by AUT-PAGE and RP-HPLC. The primary structure of four alpha globins was analyzed by combined mass spectrometry approaches. Two of these globins had never been sequenced before. One was a new alpha variant, an allele of the HBA1A gene from which it differed for the mutation A26T and has been registered with a low frequency only in Apulian breeds; the other was a globin encoded by the HBA2 locus, whose primary structure was previously derived from the corresponding gene. The two alleles recorded at the HBA2 locus presented a different frequency in the three breeds but may be considered to be generally rather common. Notwithstanding the sample size no goat was found to exhibit HbA1B. The authors discuss their findings in the light of the results reported by other researchers and argue that, in spite of what had been inferred in pioneer works on goat hemoglobins, HBA1B is not a common allele.

Characterization by RFLP analysis, of the Caprine beta-globin gene cluster in Norwegian dairy goats

Restriction fragment length polymorphism analysis has been used to characterize the beta-globin cluster in Norwegian dairy goats. Several polymorphic Taq I restriction sites were identified by double digestions with Bam HI, Hind III, and Eco RI, and restriction maps of the different beta C, beta A and beta F alleles were established. Allelic association between the previously established beta-globin types at the protein level and specific Taq I alleles was found. Furthermore, a preferential association between certain RFLP haplotypes and beta-globin types was observed.

Hemoglobin types in Saanen goats and Barbary sheep: genetic and comparative aspects

By the use of the Immobiline technique at pH ranges 7.0-7.6 and 6.9-7.9, 16 different hemoglobin (Hb) phenotypes were observed in 61 English Saanen goats. They are explained in this breed by a genetic theory of five beta-globin genes (A4, A6, A8, E, and D) and two closely linked alpha-globin loci ('alpha and "alpha) of which the "alpha has a variant allele, provisionally called "alpha X. Family data together with observed and expected Hb frequencies were in agreement with the genetic theory. Among six Barbary sheep there were three Hb phenotypes explained by the occurrence of the beta-chain alleles B and Cna.