Sunshine and the geographical distribution of the alleles of the Gc system of plasma proteins

Abstract

Following the discovery by Daiger et al. (1975) that the Gc proteins of human plasma act as the carriers of vitamin D, the authors have plotted on a world map all available data on the frequency of the allele Gc2, and compared the distribution with that of sunlight. With some exceptions high frequencies of Gc2 correspond to low levels of sunlight and vice versa. Similar comparisons within Ireland show no such relation. The results are discussed in relation to natural selection and the incidence of rickets, due to vitamin D deficiency.

Geographical cline of allele frequency of group-specific component (GC) in the Japanese populations: An analysis of data obtained by immunoelectrophoresis

“…Walter and Steegmtiller (1969) have reported that GC*2 frequencies tend to decrease from north to south in the Old World. Mourant et al (1976) frequency from north to sourth in the Chinese populations (Nakajima and Ohkura, 1971) is well-explicable by the above hypothesis. Another explanation may be given that such a cline was formed by gene flow in past spreads of populations acquiring high GC*2 frequency in dull climates.…”

“…Data on the racial and geographical variations of GC allele frequencies have been accumulated and analyzed (Walter and Steegmtiller, 1969;Mourant et aL, 1975Mourant et aL, , 1976.…”

Group-Specific Component (Gc) Subtypes in the Indian Subcontinent

“…This diverse historical affiliations of the tribal groups could be one of the factors to account for the genetic diversity seen here, but at the same time a possible role of a yet unknown selection cannot be ruled out. Mourant et al [1976] proposed an inverse correlation of Gc*2 allele with the degree of insolation, and more recently a direct correlation was suggested with Gc*lF al lele [Papiha, 1986], Matsumoto et al [1980] proposed a selection due to skin pigmen tation as a possible explanation to account for the variation of Gc frequencies be tween Mongoloid populations from North and South-east Asia. Such variation of pigmentation, although not yet studied in India, is quite visible in tribal popula tions from North-west, North-east and South India.…”

Synthetic review on the different anthropological aspects of hemoglobinopathies in Tunisia

“…Anthropologists, interested by genetic relationships analyses of human populations and the study of their evolutionary history, have initially used classic genetic markers such as those of ABO blood groups (Mourant et al, 1976), the PI system of alpha 1 antitrypsin (for review see Denden et al, 2012), HLA loci, Rhesus system (e.g., Sanchez-Mazas and Langaney, 1988;Chaabani et al, 2000;Arnaiz-Villena et al 2010) and particularly those of immunoglobulin GM system known by its unparalleled ability, of a single system, to differentiate human populations (Chaabani, 2002). These studies have demonstrated that the gene pool is not a simple sum of genes, but is a dynamic system, which is hierarchally organized and which maintains the memory of past events in the history of populations.…”