PubMed Health⌕ Search

Biomedical subjects

R G Somes

Publications and source records attributed to R G Somes.

At least 37 records · Page 2Linked to original sources
PubMed1968

Microcirculation: loss of an enzyme activity in chickens with hereditary muscular dystrophy.

Histochemical localization of an alkalinie phosphatase, with (alpha)-naphthyl phosphate used as substrate, shows that activity in breast muscle from normal chickens is restricted to the microvasculature. In chickens with hereditary muscular dystrophy, this enzyme activity disappears from capillaries and small arterioles before degeneraction of muscle fibers is detectable. This loss is retarded in myopathic chickens that have received oxygen therapy.

Alkaline Phosphatase↗
PubMedDate not supplied

Recessive inherited doubling of the chicken's uropygial gland papilla.

A new mutation that causes doubling of the uropygial gland (oil gland) papilla is described, and data that demonstrate its inherited basis are presented. This condition, which has been given the name "double oil gland papilla," varies in its expression: some individuals show only an indention of the papilla tip, while others exhibit a complete cleavage of the papilla such that two completely separate papillae project from a single oil gland. The data presented show that a single autosomal recessive gene, dgp, is the main determinant of this trait, but that its expression may also be influenced by background genetic factors as well as sex. Males more frequently are of the extreme doubling expression while females more frequently express the milder indented phenotype. Approximately 4% of mutant females are classified as normal. A linkage test with the rose comb gene showed independent segregation.

Animals↗
PubMedDate not supplied

Alphabetical list of the genes of domestic fowl.

An alphabetical list of over 250 loci of the domestic chicken is presented. Also included is a set of nomenclature rules and a proposal that the prefix Ea (erythrocyte antigen) be used with blood group symbolism in order to distinguish them from other loci with the same letter designation. These proposals grew out of the 1977 symposium on "Mutant Nomenclature and Gene Symbolism".

Animals↗
PubMedDate not supplied

Ear tuftedness: a lethal condition in the Araucana fowl.

The lethal effects of the ear-tuft trait of the Araucana chicken are reported and the genetic basis of its inheritance is verified. The ear-tuft (Et) gene acts as an autosomal dominant with reduced penetrance in heterozygotes. This study gave two estimates of reduced penetrance, 4 and 14 percent. Homozygotes die during 17-19 days of incubation, although a few may hatch. Most of these die within a week, but occasionally an "escaper" will live to maturity; one such Et/Et individual was verified. Heterozygotes also experience increased embryonic mortality at about 20 or 21 days of incubation. In this study the average embryonic mortality among heterozygotes was 41.6 percent. Posthatch mortality also was significantly greater among tufted chicks than among nontufted chicks.

Animals↗
PubMedDate not supplied

Dominant white plumage-color somatic mosaic in the domestic fowl.

An unusual feather-color mosaic of the variegated type is described in the fowl. The bird, a female, has the e+/e+ wild-type plumage pattern with light tan or buffish colored feathers intermingled over her sides and dorsal surface. This condition is bilateral and symmetrical with whole feathers being diluted in some areas and parts of feathers in others. Breeding tests with e+/e+ males showed that the bird was heterozygous for dominant white (l/i+) and homozygous for e+. All her e+/e+, l/i+ offspring were of the red-pyle pattern as would be expected from that genotype. The possible cause of this mosaic condition may be due either to the loss of the l-bearing locus or to a reverse mutation to i+ in neural crest cells destined to become the primordial melanoblasts.

Animals↗
PubMedDate not supplied

Inheritance of the henny-feathering trait of the Sebright bantam chicken.

The henny -feathering trait of the Sebright bantam chicken is the result of an enhanced rate of estrogen synthesis (aromatase activity) in skin and other peripheral tissues of this bird. To gain insight into the underlying nature of this mutation, we examined the inheritance of this trait using a sensitive isotopic assay for aromatase activity. All birds of the F1 generation obtained by crossing homozygous henny X non- henny chickens expressed increased aromatase in the skin, and the males exhibited henny -feathering plumage. The average rate of aromatase activity in the skin of F1 chicks was approximately half that of homozygous henny chicks. The distribution of increased aromatase activity in the F2 generation and in the backcrosses of F1 to the two types of parental strains suggest that the enzyme activity in extragonadal tissues is regulated predominantly by one autosomal gene. Attempts to demonstrate linkage to several known loci by backcrossing F1 heterozygotes with parental chickens carrying a variety of genetic markers were unsuccessful. We conclude that the enhanced estrogen synthesis in extragonadal tissues in chickens carrying this gene is inherited as an autosomal codominant but that a half maximal level of the enzyme is sufficient to allow full development of female feathering in affected male birds so that henny -feathering is transmitted as a dominant trait.

Animals↗
PubMedDate not supplied

Hereditary congenital baldness: a sex-linked trait in the domestic fowl.

Congenital baldness in the domestic fowl is a genetic condition in which small irregular skin areas are devoid of down feathers (and later definitive feathers) over one or both eyes and/or the center of the head. In this study, the expression of congenital baldness was quite variable and ranged in size from a few follicles to areas as large as 10 mm2. The area over the right eye and the center of the head was more frequently involved than was the area over the left eye. This condition was inherited as sex-linked recessive. The symbol ba was assigned to the gene, and it was shown to be linked to the sal locus by 7.6 to 8.2 crossover units. An unusual feature was that 5% to 13% of heterozygous males exhibited the trait.

Alopecia↗