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T J Robinson

Publications and source records attributed to T J Robinson.

At least 91 records · Page 5Linked to original sources
PubMed1983

Protein variation and its systematic implications for the South African Leporidae (Mammalia:Lagomorpha).

Analysis of 9 genetic loci by horizontal starch gel electrophoresis was performed on 203 specimens of South African representatives of the leporid genera Lepus and Pronolagus. Three loci were found to be polymorphic within samples of the various species of both genera: transferrin (Tf-I), esterase-1 (Es-I) and esterase-2 (Es-II). Only one system, carbonic anhydrase (CA-I), proved useful in species identification, this being restricted to the genus Lepus. Based on this system all Lepus specimens analysed would be assigned to one of two groups corresponding to the species L. capensis and L. saxatilis.

Animals↗
PubMed1983

Karyotypic conservatism in the genus Lepus (order Lagomorpha).

The G- and C-banded chromosomes of six species of hare (genus Lepus) are presented and compared. No variation in gross chromosome morphology or banding pattern was observed indicating that speciation in this widespread genus has not involved karyotypic change.

Animals↗
PubMed1983

Evolution of chromosomal variation in cottontails, genus Sylvilagus (Mammalia: Lagomorpha): S. aquaticus, S. floridanus, and S. transitionalis.

The banding patterns of mitotic chromosome from three cottontail species, Sylvilagus aquaticus (2n = 38), S. floridanus (2n = 42), and S. transitionalis (2n = 46), are presented and compared with those of the proposed leporid ancestral karyotype, the latter being reflected in a species of hare, Lepus saxatilis (2n = 48). The differences in the diploid numbers of the cottontail species are primarily due to the fixation of Robertsonian fusions which have occurred during the evolution of their respective genomes. Of the eight fusion products identified, seven were species specific, while one, which is thought to reflect their more recent common ancestory, is shared by both S. aquaticus and S. floridanus. Other karyotypic differences include interspecific variation in the amount and distribution of constitutive heterochromatin, as well as the presence of two autosomal pairs in S. transitionalis which do not have apparent banding homologies either with the chromosomes of other cottontails or with those of the Lepus genome. The tendency for certain chromosomes in the ancestral karyotype to show a predisposition to undergo fusion events within the Leporidae is discussed.

Animals↗
PubMed1980

Comparative chromosome studies in the family Leporidae (Lagomorpha, Mammalia).

Chromosome banding patterns of Lepus saxatilis, 2n = 48, and Pronolagus rupestris, 2n = 42, are presented. Comparison of G-banded karyotypes allows the identification of similar elements in both species. The karyotype of P. rupestris differs from that of L. saxatilis by the presence of three fusions in the former. Comparative studies with the fusion products of Oryctolagus cuniculus indicate that fusion and not fission is the major factor in chromosomal evolution of these leporids. The chromosomal conservatism of the hares is compared to the karyotypic variability of the rabbits and possible causes are discussed.

Animals↗
PubMed1979

Erythrocytes: a new cell type for the evaluation of insulin receptor defects in diabetic humans.

Human erythrocytes have specific insulin receptors. When studied in an insulin radioreceptor assay, erythrocytes from adult-onset, nonobese diabetic subjects bound at least 42 percent less insulin than the normal subjects at insulin concentrations from 0.1 to 100 nanograms per milliliter. The diabetic subjects had 190 insulin receptor sites per cell as compared with the 380 insulin receptor sites per cell for the normal subjects. The deficit of insulin binding in the diabetic subject was thus associated with a fewer number of insulin binding sites per cell with little or no change in affinity. The erythrocyte is a readily available cell for the evaluation of cellular insulin receptor activity.

Adult↗
PubMed1979

The chromosomes of the southern elephant seal, Mirounga leonina (Phocidae: Mammalia).

Chromosome analyses were carried out on bone marrow cells from three elephant seal pups (Mirounga leonina), a species characterized by a 2n = 34 chromosome number. Arm ratios for the different chromosomes were calculated to facilitate the classification of chromosomes into groups. The karyotype of the southern elephant seal differs from other reported 34-chromosome phocids in the morphology of the Y chromosome and in that of one of the autosomal chromosome pairs.

Animals↗
PubMed1977

Coeliac disease and goitre.

Two cases of coeliac disease associated with thyroid enlargement are presented. One had a large simple adenomatous goitre which was removed surgically and the other had histological confirmation of lymphadenoma (Hashimoto's disease).

Celiac Disease↗
PubMed1976

Coeliac disease with farmers' lung.

Two patients with allergic alveolitis due to mouldy hay antigens (farmer's lung) were shown to have malabsorption due to coeliac disease. As similar associations have been found with other alveolar diseases, this association is probably not fortuitous and further population screening should be done.

Adult↗