Associations between marker genotypes, halothane reaction, CC activity and meat quality characters in a sample of German Landrace pigs

Routine blood typing of German Landrace pedigree populations and an earlier study revealed very low frequencies of the favourable alleles at the marker loci Phi, Pgd and H . The hypothesis was that in this population the whole linkage group of favourable alleles at the halothane and neighbouring marker loci may have been lost as a consequence of intense selection for leanness and type. The present study of 1050 German Landrace pigs at the Relliehausen experimental station, where some effort has been made to maintain a higher frequency of the favourable alleles Phi^A (0.48), H- (0.43) and Pgd^A (0.70) gave quite different results.
The frequency of halothane-positive pigs found by using a severe test was only 30 %. Only 5.4 %, 8.8 %, 13.4 % and 13.9 7% of animals with Phi^AIA, H^-I-, Pgd^A/A and Phi^A/B genotypes respectively were halothane-positive. Forty to sixty per cent of pigs with these marker genotypes could therefore be expected to be homozygous halothane-negative ( N/N ) animals. Creatine kinase activity and three selected meat quality characters showed highly significant differences between the A/A and the B/B genotypes for the marker loci Phi and Pgd , with the heterozygotes being intermediate. These differences are greater than those observed between halothane-negative and halothane-positive phenotypes. The only other consistently superior marker genotype in this population was the H blood group genotype H -^I- . In contrast to findings from Sweden and Switzerland, the postalbumin locus Po2 and the suppressor locus S for the A-O blood groups did not exhibit useful marker qualities.
It is concluded that in the German Landrace the marker loci Phi, Pgd and H could also be helpful in breeding homozygous halothane-negative pigs with distinctly better meat quality characteristics.     

Lewis a blood group antigen of non-secretors: a receptor for candida blastospores

Abstract This study tested the hypothesis that the Lewis ^a blood group antigen found predominantly on the cells of non-secretors might be one of the receptors for Candida species. Binding of strain 3118C to epithelial cells from either secretor or non-secretor donors was not inhibited by treating the cells with anti-Lewis ^a or anti-Lewis ^b antisera. Binding of strain 3091 to non-secretor cell was inhibited by pretreating the cells with anti-Lewis ^a, but this was not observed for secretor cells.
The results suggest that Lewis ^a might be one of the receptors for some yeast strains.     

The blood group factor Kf and allele Kae in the pig

By means of alloimmune reagents used in the indirect Coombs test and the dextran test a new factor Kf in the K bloodgroup system of pigs was found, controlled by alleles K ^acf, K ^acef and K ^bf. A new allele K ^ae was also detected.
The K system with 6 alleles, 11 phenotypes and 21 combinations of genotypes remains (from the genetic point of view) an open system.     

Serum albumin polymorphism and its relationship to economic traits in crossbred cattle

The serum albumin genotypes of 65 Jersey × Hariana (F₁), 75 Holstein Friesian × Hariana (F₁) and 47 Brown Swiss × Hariana (F₁) crossbred cows were determined by starch gel electrophoresis. Two albumin alleles Alb^F and Alb^s , but only either as Alb^F homozygotes or Alb^Fs heterozygotes, were observed amongst these animals. There were no Alb^S homozygotes or other genotypes. Highly significant relationships between albumin genotypes and both birth weights and first-lactation milk yields of these cows were observed. The Alb^F allele was associated with increased milk yield and greater birth weights.     

Further contribution to the H blood group system in pigs

The haemolytic reagent allowing direct serological detection of He homozygous pigs was obtained by the immunization of a Landrace sow. Another monospecific reagent prepared from immune serum of a Miniature pig made possible the evidence for a new factor of the H system - He. This factor is genetically controlled by the allele H ^be. Its frequency in Miniature pigs was 0.099.
The H system with alleles H ¹=H^a, H²= H^b, H³= H^ab, H⁴=H^cd, H⁵= H^bd, H⁶=H^be and H⁷= H- continues to be a genetically open system.     

The Expression of X-Linked Phosphoglycerate Kinase in the Early Mouse Embryo

Abstract. During early mouse embryogenesis, the activity of X-chromosomally linked maternal and paternal phosphoglycerate kinase (PGK-1) alleles was determined using electrophoretic separation of their gene products and a sensitive fluorometric enzyme assay. In the embryos collected from females homozygous for PGK-1^b mated with PGK-1^a males and vice versa, the paternally derived allozyme was first detected after implantation on day 6. Expression of the maternally inherited allele was studied in embryos from females heterozygous for PGK-1^b and PGK-1^a. From day 1 to day 4, the embryos maintained a constant ratio of enzyme activity of PGK-1B to PGK-1A. Prior to implantation of the embryos between day 4 and day 5, the activity ratio of the two PGK-1 allelic variants changed significantly due to the first appearance of newly synthesized PGK derived from the maternally inherited allele.
Our data demonstrate a temporal difference in the onset of PGK synthesis depending on whether this particular gene product is of maternal or paternal origin. Therefore, we conclude that the maternal PGK-1 locus is already activated during late preimplantation development whereas the paternally inherited gene locus remains silent at the preimplantation stage but is subsequently expressed at approximately the time of X-chromosomal inactivation.     

The genetics of an electrophoretic variant of an erythrocytic protein in the house mouse (Mus musculus)

An electrophoretic mobility variant of a protein band anodal to haemoglobin in alkaline starch gels was found in wild house mouse populations in South Australia. Most wild mice and all inbred lines examined are homozygous for the Erp-1 ^a allele at the locus controlling this variation. The rare allele Erp-1 ^b, which has a frequency of about 1% in South Australia, produces a protein band of slower mobility in alkaline gels. Homozygotes show one protein band whilst the heterozygote has three bands. The Erp-1 protein does not appear to be haemoglobin or carbonic anhydrase. The Erp-1 locus is closely linked to Es-1 on chromosome 8 with a recombination fraction of 6.04 ± 1.32%.     

Oxygen and acid-base status related drives to gill ventilation in carp

Gill ventilation in carp Cyprinus carpio increased 50% with a reduction of [O²]^a to 60% of the control value. Small decreases of inspired PO² also increased ventilation, which occurred without any significant changes of the blood gas picture. Ventilation increased with hypercapnia but only if [O²]^a became reduced by concomitant Bohr and Root shifts. Consistently, hypercapnia failed to increase ventilation when combined with hyperoxia. Therefore, it was not possible to ascribe any ventilatory response to specific CO²/pH receptors.     

Genetic polymorphism of the vitamin D binding protein (Gc) in the musk shrew (Suncus murinus)

In the musk shrew ( Suncus murinus ), the electrophoretic bands in the post-albumin region were identified as vitamin D binding protein (Gc) by the [³HI vitamin D₃ binding method. Three Gc phenotypes were distinguished from each other: a single faster band (Gc-A), a single slower band (Gc-B) and the double bands (Gc-AB). Results of mating experiments indicated that the Gc-A and Gc-B are controlled by two codominant alleles, Cc ^a and Gc ^b at an autosomal locus ( Cc ), respectively. It was noticed that, in the Gc-AB phenotypes, the Gc-B band was constantly more intense than the Gc-A band in the protein staining. The same tendency was also observed btween the homozygous Gc-A and Gc-B bands, and further, radioactivity of the Gc-B bound with [³H] vitamin D₃ was about twofold higher than that of the Gc-A. These results suggest that the Gc^b yields its protein product twofold more than the Gc ^a. No cross-reaction between the shrew proteins and a rabbit anti-human Gc protein was observed.     

Evidence for the Tf locus being associated with an early lethal factor in a strain of pigs

The frequencies of three co-dominant alleles Tf ^A, Tf ^B and Tf ^c controlling the serum transferrin locus in native and exotic breeds of pig in the United Kingdom are shown. Matings between different transferrin genotypes and segregation of the transferrin alleles in piglets from 131 litters are also recorded.
In eleven litters from matings within a closely related group of animals heterozygous for the Tf ^c allele, no offspring of the Tf ^c/ Tf ^c genotype were born. Matings between heterozygous related boars believed to be carrying a lethal factor linked to the Tf locus and heterozygous unrelated sows of the Saddleback breed, resulted in offspring of the Tf ^c/ Tf ^c genotype being born.
An excess of heterozygote genotypes was found in all litters from matings between animals heterozygous for the Tf ^c allele. In all these litters the average litter size was 0.5 piglets less per litter than the average for all other litters studied. For the eleven litters from matings involving closely related animals heterozygous for the Tf ^c allele, the average litter size was 1.4 piglets less per litter than the average for all other litters.
The possibility of an early lethal factor being linked to the Tf locus in this family of pigs is discussed.     

Genetic control of liver esterase forms in chickens

Six regions of esterase activity designated I to VI were resolved from liver extracts of chickens by horizontal starch gel electrophoresis. These esterases were further characterized on the basis of their substrate affinities and differential responses to various inhibitors.
Genetic variation was found in esterases of region VI which appeared to be ali-esterase. Four phenotypes, A, B, AB and O, were observed. These phenotypes were shown to be controlled by one autosomal locus, designated Es-3 , with alleles Es-3 ^A, Es-3 ^B and Es-3 ^O. This locus is not closely linked to the blood group loci A and B , serum alkaline phosphatase ( Ap ), liver acid phosphatase ( Acp-2 ) and serum esterase ( Es-1 ) loci.     

Interaction of the B locus and the GVHR-selected lines in the graft-versus-host reaction in chickens

Genetic differences affecting the degree of splenomegaly in the graft-versus-host reaction (GVHR) of chickens were studied. Two B genotypes, B⁹B⁹ and B¹¹B¹¹, and two GVHR-selected lines, H and L, were examined. The degree of splenomegaly of B⁹ B⁹→ B¹¹B¹¹ was significantly higher than that of B¹¹B¹¹→ B⁹B⁹ for all line combinations. In contrast, the inoculation of H into L gave consistently higher splenomegaly than that of L into H. This suggested that the effects of B locus were higher in hosts than in donors, while those of the GVHR-selected lines were higher in donors than in hosts.
The analysis of variance revealed that both the differences between the reciprocal combination of B genotypes and between the GVHR line combinations were statistically highly significant. Furthermore, the interaction of B genotypes and GVHR lines was also highly significant.     

Genetic control of the immune response in lines of chickens selected for graft-versus-host competences

The immune response of chickens to goat erythrocytes has been examined. The H line selected for high competence of graft-versus-host reaction (GVHR) showed higher immune responses than the L line selected for low GVHR competence. It appeared also that immune responses were controlled by the B blood group locus, which is the major histocompatibility locus in chickens. The relative immune responsiveness of B genotypes were B ¹¹/¹¹> B ⁹/ B ¹¹> B ⁹/B⁹.
Treatment of antiserum with 2-mercaptoethanol (2-ME) proved that the difference in immune responses between lines was due mainly to the 2-ME resistant antibody and that the difference between the B genotypes was due to the 2-ME sensitive antibody.     

Allele Ebdgjmr (E17) in the pig E blood group system

Summary. A comparison of the standard E reagents provided clear evidence for the allele E^bdamr (E¹⁷) in Danish Landrace and wild pigs.     

Genetic polymorphism of the sixth component of complement (C6) in the pig

Summary
Using agarose gel isoelectric focusing and immunoblotting with rabbit anti-rabbit C6, a genetic polymorphism has been found in the sixth component of complement (C6) in six breeds of pigs. The C6 locus was highly polymorphic. Family data indicated that pig C6 pheno-types were inherited by means of five codomonant alleles named C6 ^A, C6 ^B, C6 ^C, C6 ^D and C6 ^E at a single autosomal locus. C6 deficiency in two of 241 individuals tested was found, which suggested the presence of a null allele in pig populations. Marked breed differences among the gene frequencies and heterozygosities at C6 locus were observed.     

Trends in economic traits, halothane sensitivity, blood group and enzyme systems of Swiss Landrace and Large White pigs

Pigs deriving from 150 breeding centres constituting a representative section of elite breeding herds (2496 Swiss Landrace pigs, 587 Swiss Large White pigs) were subjected to blood typing during the period 1981 to 1984. Production traits such as daily gain, feed conversion ratio, lean meat content and meat quality score were available to show the trend in these performance traits since 1978. Field data on the halothane reaction of 14 270 Swiss Landrace (SL) pigs were used to assess the porcine stress syndrome during the period 1978–1983.
In SL pigs the frequency of the alleles H^a, Phi^B and Ada^A decreased significantly, and that of the H^c and Phi^A increased during the period of the study. The frequency of the H^a allele dropped from 0.36 in 1981 to 0.20 in 1984, whereas the H^c allele rose from 0.22 to 0.37. In Swiss Large White (SLW) pigs, on the other hand, the frequency of the H^a allele increased constantly from 0.31 to 0.37 during this period.
An initial frequency of 17.7 % (1978) halothane reactors in SL pigs was lowered to 0.7 % (1982) after five years of halothane testing.
In SL pigs the meat quality scores improved regularly, whereas in SLW pigs it did not change very much. The percentage of PSE animals in the SL breed was reduced from 32.7 % in 1978 to 7.1 % in 1983.
Because the Hal locus is associated with production traits such as meat quality, linkage disequilibria could explain the observed associations between the H and Phi types and production traits.     

The genetic control of arylesterase activity in the serum of Gotland Sheep

Esterase activity was determined in 955 serum samples of Gotland sheep. The activities showed a wide range and could be distinguished in six types. Family data were in agreement with the theory of three multiple alleles controlling the esterase activities (Lee, 1966). The following gene frequencies were estimated: Es ^a= 0.15, Es ^b= 0.75 and Es ^c= 0.10. The Es ^a allele controlled an enzym with high hydrolysis rate of α-naphthyl acetate, medium high of β-naphthyl acetate and low of indophenyl acetate. The enzym controlled by the Es ^b allele had medium high hydrolysis rate of α- and β-naphthyl acetate and relatively high of indophenyl acetate. The enzym of the Es ^c allele had low activities for all three substrates. The hydrolysis rate was increased by the addition of calcium. In starch-gel electrophoresis the esterase types could be divided in four groups due to the staining intensity of the arylesterase zone but no difference in migration rates was observed.     

Morphological and chromosomal descriptions of new species in the Anopheles subpictus complex

Abstract. Anopheles subpictus Grassi is shown to comprise four reproductively distinct species, designated A, B, C and D, occurring sympatrically in villages of Pondicherry, southeast India.
Adult females were reared individually from wild larvae and examined for their morphological and chromosomal characters. Paracentric fixed inversions on the X-chromosome serve to distinguish the species cytogenetically, with no inversion heterozygotes (i.e. no interspecific hybrids) among totals of 717 species A (X+^a,+^b), 1863 species B (Xa, b), 869 species C (Xa,+^b) and 1365 species D (X +^a,b) identified.
Morphologically, diagnostic characters for each of the four species are seen in the egg float ridge number, larval mesothoracic seta 4, pupal seta 7-1 and the palpi of female adults. Species A. C and D immatures inhabit freshwater, whereas the malaria vector species B breeds in saltwater and was found only in coastal villages.     

Linkage between the H and 6-Pgd Loci in Pigs)

The designation H stands for a blood group system and its corresponding chromosomal locus in pigs. The system includes multiple alleles, but merely two of these, Ha and Hc, were involved in the present investigation. The two alleles are co-dominant and form a closed system in the Duroc breed (Andre-sen 1963, 1964). The results of the present study using pigs of the Danish landrace breed and particularly the Duroc breed have shown that electrophoretic variants of the enzyme 6-phospho-gluconate dehydrogenase (6-PGD) in the erythrocytes likewise are determined by two alternative alleles, A and B, in pigs of both breeds. Thus, in agreement with observations by Saison (1968), who studied various other breeds and their crosses, three electrophoretic patterns were observed among the pigs studied. The three patterns or types appear as bands in the starch-gel after the addition of substrate. They are designated as A, AB and B. They correspond to the genotypes AA, AB and BB.     

Gene order and recombination rates in the linkage group S-Phi-Hal-H-(Po2)-Pgd in pigs

Families of Czech Landrace (94 litters and 636 offspring) were tested for halothane sensitivity, A-O (S), H, PHI and PGD phenotypes. Informative matings for the estimation of recombination rates between marker loci were selected. The following recombination frequencies were established: S-Phi = 4.8 % (2.5 % -10.7 %);S-H = 6.8 % (4.3 %-11.7 %); Phi-H = 2.6 % (0.9 %-5.3 9%); H-Pgd = 4.4 % (1.6 %-8.0 %). CCCC-overs were observed also between S- Hal, Hal-H andHal - Pgd, but were not found between Phi - Hal. On the basis of these results it has been possible to revise the position of the S locus in this linkage group. The most probable gene order would be: S - Phi - Hal (or Hal - Phi) -H- (P02) - Pgd.
A striking difference was found between the number of halothane-sensitive pigs (87) and HalⁿHal ⁿ genotypes determined by haplotyping (123). Segregation rates in 19 backcross matings and experimental matings of the animals proved that this difference is mostly due to incomplete CCC or low expression of halothane sensitivity.