TRANSFERRIN VARIATION IN COLUMBIDAE

Relationship between rabbit transferrin electrophoretic patterns and plasma iron concentrations

Rabbit transferrin (Tf) was studied electrophoretically using 1141 blood samples from individuals belonging to seven populations (Spanish Common, Spanish Giant, Butterfly, Lyoné de Bourgogne, New Zealand White, Californian and New Zealand White X Californian hybrids). No Tf polymorphism was found by starch gel electrophoresis, but six patterns, differing in the presence and/or intensity of three bands ('a', anodic; 'b', intermediate; and 'c', cathodic) were observed by polyacrylamide gel electrophoresis. No genetic model could explain these patterns, since they reflect differences in plasma Tf iron content. The electrophoretic test allowed a direct observation of the relative in vivo levels of the different Tf molecular species; saturated (band 'a', Fe2Tf); semi-saturated (band 'b', Fe1Tf); and without iron (band 'c' Fe0Tf, apotransferrin). The degree of iron saturation of Tf varied among individuals and throughout the individual's life. Specifically, in pregnant females, Fe2Tf and Fe1Tf are generally observed, except in late pregnancy (from day 25 to parturition), when mainly apotransferrin is observed. Significantly, within 24 h post-partum, high levels of Fe2Tf are reached in the female's serum.

Protein polymorphism in a feral population of the pigeon Columba livia domestica

Sixteen enzymatic and non-enzymatic proteins of the pigeon Columba livia domestica were examined electrophoretically. These proteins were presumed to be under control by 22 loci. Of the 22 loci, 6 were defined as polymorphic and 15 as monomorphic. Another locus was variable, but the variation was not genetically interpretable. Average heterozygosity calculated over 21 loci was 0.075.

Loss of genetic variability at the transferrin locus in five hatchery stocks of tambaqui (Colossoma macropomum)

Knowledge and conservation of the genetic variability in stocks maintained as live gene banks have become a high priority task for Brazilian fish culture. The aim of the present survey was to assess the transferrin allelic diversity of five hatchery stocks of tambaqui (Colossoma macropomum). The tambaqui stock from Pentecoste, the oldest maintained in Brazilian hatchery stations, retained three of the six alleles detected in wild populations of tambaqui from the Amazon River. Other hatchery stocks, directly or indirectly derived from the Pentecoste stock, did not show transferrin allelic variability. Insufficient number of founders and genetic drift due to sampling errors seem to be the main causes leading to loss of genetic diversity in tambaqui hatchery stocks. Appropriate management strategies are required in order to improve the genetic potential of tambaqui stocks in Brazil.

A comparison of the structure and properties of serum transferrin from 17 animal species

1. A comparison of the chemical and physical properties of the iron transport protein transferrin, purified from the following seventeen animal sera, is reported; human, rhesus monkey, dog, cat, rabbit, guinea pig, mouse, rat, cow, sheep, goat, horse, pig, turkey, duck, turtle and rattlesnake. 2. Similarities and differences in molecular weight, isoelectric point, antibody specificity, effect of pH on iron release, number of sialic acid residues, amino acid composition and the N-terminal amino acid residue, are discussed. 3. The results are compared with the commonly accepted evolutionary origins of the 17 species.

Evolutionary relationships of a "primitive" shark (Heterodontus) assessed by micro-complement fixation of serum transferrin

The evolutionary relationships of six sharks were investigated by comparing their transferrins using the micro-complement fixation method. The immunological distances observed were used to build a tree that confirms that the squaloid and galeoid species examined belong to two separate groups and that Heterodontus, a genus of hitherto uncertain position, belongs with the galeoids. The divergence time estimated from the transferrin comparisons is roughly 240 +/- 65 million years between Heterodontus and galeoids.

Transferrin, haematological indices and liver glycogen in field mice collected from a coal mining area and a control site in Poland

A polymorphism for serum transferrin in field mice from polluted and control sites was compared with body-morphological and haematological parameters, and with liver glycogen concentration. The distribution of genotypes in the polluted area was not panmictic, due to higher frequencies of the rare allele Trf(c) occurring mainly in males. In the polluted area, transferrin-c was accompanied by slowly migrating, Fe-binding protein fractions. Since the Trf(c)/Trf(c) homozygote possessed higher red blood cell parameters, it is suggested that these extra proteins have an Fe-transport function. The morpho-physiology of heterozygotes from the polluted area did not differ significantly from those from the control site. The animals from the polluted area possessed a high concentration of liver glycogen, indicative of poor environmental conditions. Also, a generally lower level of red blood cell parameters suggests that non-oxygenic processes dominate over oxygenic ones in the polluted area.

The use of artificial gynogenesis in studies on the immune system of carp (Cyprinus carpio L.)

Gynogenetic carp were obtained by using gamma-irradiated sperm for fertilization followed by a cold shock. The gynogenetic fish and normal siblings of the same parents were analysed for 3 genetic markers: scale pattern, transferrin (Tf) and allograft rejection. Gynogenetic offspring showed only the maternal scale pattern (scattered). In the majority of the gynogenetic fish a heterozygous Tf pattern identical to the mother was observed. Animals homozygous for Tf were rare in this group. A typical paternal Tf band was only seen in normal siblings. An exchange of skin grafts between normal animals was always followed by rejection (median survival time, 12 days at 23 OC). However, the rejection was delayed in the gynogenetic group (MST, 19,6 days). There were even signs of acceptance in some animals. This approach can be used for the identification of 2nd and 3rd generation gynogenetic fish, which are homozygous for certain MHC haplotypes.

Variability of hematocrit value, blood serum beta- and gamma-globulin level and body weight in different transferrin genotypes of common vole (Microtus arvalis, Pallas 1779) from natural population

1. Heterozygotes TfF/TfE of voles did not differ in body weight, they had higher hematocrit value (males and females), higher beta-globulin fraction (males) or higher gamma-globulin fraction (females). 2. A smaller variability of parameters studied was observed in heterozygotes than in homozygotes. Small and similar variability occurred in hematocrit value and beta-globulins while higher variability occurred in body weight and gamma-globulins. 3. In common voles the faster migrating E system of transferrin may have a higher capacity for iron transport than the F system. 4. Seasonal changes of hematocrit value in vole populations seems to result from genetical and physiological variability. 5. Sexual and seasonal changes in beta-globulin level appear to be related to changes in sexual activity of the animals during the seasons. 6. In autumn, low weight of animals and high serum gamma-globulin level, with the same physiological variability of these two parameters, suggest the synthesis of gamma-globulins with tissue (muscle) proteins. 7. Autumnal increase of gamma-globulin level seems to be very important, taking into consideration the role of the protein in water retention and its filtration from the tissues. Very high level of the protein fraction may play a role in winter high mortality of voles.

A simplified electrophoretic system for determining molecular weights of proteins

Electrophoresis of 31 different proteins in commercially prepared polyacrylamide gradient gels, Gradipore, yields a linear relationship between a hypothetical limiting pore size (the reciprocal of a limiting gel concentration, GL) and the cube root of the mol.wt., over the range 13 500-9000 000. A regression analysis of these data reveals that 98.6% of all variability in 1/GL is explained by the molecular weight, and this degree of accuracy compares favourably with existing methods for the determination of molecular weight by retardation of mobility in polyacrylamide. This new procedure has the additional advantages that molecular-weight standards can be obtained from readily available body fluids or tissue extracts by localizing enzymes and other proteins by standard histochemical methods, and that the same electrophoretic system can be used in determining molecular weights as is used in routine surveys of populations for individual and species variation in protein heterogeneity.

An electrophoretic description of five species of squirrel

1. The blood serum proteins of five species of Nearctic squirrels were electrophoretically examined. 2. Protein polymorphism was detected in all the species described. 3. The use of the mean relative mobility of specific proteins was shown to be a valuable aid in distinguishing species.

An electrophoretic polymorphism in the serum transferrins of Praomys (Mastomys) natalensis

Three serum transferrin phenotypes of Praomys (Mastomys) natalensis, and African rodent having a high incidence of many varieties of spontaneous neoplasms, were detected by electrophoresis and autoradiography. On electrophoresis, transferrin of Trf-K was found to be a protein that migrates slowly toward the cathode, whereas that of Trf-M migrates rapidly. Trf-KM is a heterozygous phenotype of the above two. Progeny testing demonstrated that these three serum transferrin phenotypes in Mastomys are probably controlled by two codominant allelic genes, Trfk and Trfm, at a single autosomal locus. The genotypes of these phenotypes may be Trfk/Trfk, Trfm/Trfm, and Trfk/Trfm.

The amino acid sequence of a carbohydrate-containing fragment of hen ovotransferrin

1. Hen ovotransferrin was treated with CNBr and fractionated by gel filtration. 2. After further treatment by reduction and carboxymethylation a carbohydrate-containing fragment of molecular weight 11990 was obtained (fragment BCd). 3. The amino acid sequence of this fragment was determined. It consists of a single chain of 94 residues. 4. The structure of a tryptic glycopeptide derived from whole ovotransferrin permitted a further eight residues to be assigned at the N-terminus of fragment BCd. 5. Heterogeneity was found at two positions. 6. Further evidence has been deposited as Supplementary Publication SUP 50045 (19 pages) at the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies may be obtained on the terms indicated in Biochem. J. (1975), 145, 5.

Maternally derived transferrin in pigeon squabs

With the use of genetically marked transferrin, a major portion of circulating transferrin from a newly hatched squab was found to be derived from the mother through the egg. The transfer is not through the parental crop milk. The squab does not accumulate enough transferrin of its own making to be detectable until it is about 8 days old. The maternally derived protein remains detectable until 14 days after hatching. The squab actively synthesizes a portion its own transferrin from hatching onward.

Genetic variation in the eel. II. Transferrins, haemoglobins and esterases in the eastern North Atlantic. Possible interpretations of phenotypic frequency differences

Comparison, by electrophoretic methods, of eel samples from Iceland, Scotland and Germany confirmed previous reports of uniformity in haemoglobin types. When liver esterases were examined, significant differences in the frequencies of phenotypes in the ‘fast’ zone of the electropherogram were found between samples from Germany and samples from Iceland and Scotland. The frequencies of transferrin phenotypes in Icelandic and Scottish eels differed significantly from those of French and American eels.

It follows that regional differences in gene frequencies probably exist within the speciesAnguilla anguilla. The implications for the ‘atlantic eel problem’ are briefly discussed.