Lactate dehydrogenase electrophoretic variant in a New Guinea Highland population.

Six examples of a variation in the LDH-A subunit have been detected in 408 samples from three exogamous clans in the New Guinea Highlands. The New Guinea variant is similar to the Memphis-4 variant. Origin of the New Guinea variant could not be traced by genealogy but it seems likely to have persisted for several generations.

Postnatal growth of intrinsic connections in mouse barrel cortex.

Surprisingly little is known about the development of connections within a functional area of the cerebral cortex. We examined the postnatal growth of connections in mouse barrel cortex during the second and third weeks after birth, coinciding with the period of rapid synaptogenesis that occurs just after the barrels first form. A barrel is a group of neurons in layer 4 of somatosensory cortex that is part of a cortical column. Each whisker/barrel column is linked anatomically and functionally to a homotopic whisker on the contralateral face. Radial groups of cortical neurons were labeled with the neuronal tracer biotinylated dextran amine in mice ranging in age from postnatal day 8 (P8; P0 is the date of birth) to adulthood. The spatial distributions of retrogradely labeled neurons in different laminae were analyzed. The barrel map in layer 4 was used as a template to compare quantitative data from different animals and to account for substantial changes in barrel and barrel field size during development. Intrinsic projections 1) innervate increasingly more distant targets within barrel cortex up to 3 weeks of age; 2) continue to form in targets after 3 weeks, effectively strengthening existing connections; 3) follow a timetable for growth that is layer-specific; 4) link more distant barrel columns in layer 4 from neurons that are found preferentially in the barrel side and the septa between barrels; and 5) form over the shortest distances between the barrel columns. These data indicate that intrinsic connections in mouse barrel cortex develop by the progressive addition of neuronal connections rather than by sculpting preliminary connections. We describe statistically significant changes in connectivity during development that may be applied to model and assess the development of connections after a variety of experimental perturbations, such as to the environment and/or the genome.

Search for a red cell enzyme or serum protein marker in amyotrophic lateral sclerosis and parkinsonism-dementia of Guam.

Frequency distributions were determined for 24 red cell enzyme and four serum protein systems, in an attempt to identify a genetic marker associated with either amyotrophic lateral sclerosis (ALS) or parkinsonism-dementia (PD), two progressive and fatal neurological disorders of unknown cause found with unusually high incidence among the Chamorros of Guam and the Northern Mariana Islands. No striking associations were identified between either disorder and any of the gene markers tested. Thus, no genetic cause is known for either disease; local environmental factors are most likely involved in pathogenesis.

Placental enzymes: a population genetic study.

A total of more than 800 placentae from six different population groups have been examined for electrophoretic variation in 13 enzyme systems. Whilst, in many instances, the phenotype designation is presumptive, having been arrived at after critical visual comparison with illustrations in the literature, a number of new alleles have been reported here and further population genetic data have been presented. Two new alleles, MPI3 and MPI4 are described in the mannose phosphate isomerase system the former in both the Port Moresby sample and in the Chinese, whilst the latter was restricted to the Chinese samples. Also, the New Guinea MDHs 3-1 phenotype has been detected for the first time in placentae. In addition, a new allele in the aconitase system, ACONs8 has been described in the Chinese samples.

Genetic variants of carbonic anhydrase in the Asian-Pacific area.

The results of extensive surveys of red cell carbonic anhydrase phenotypes in the Asian-Pacific region are presented together with data on the occurrence of three new polymorphisms present only in Australian Aboriginals. Two of these systems are widespread right across the Australian continent, while the remaining one is restricted to members of a single linguistic group in Arnhem Land. Further examples of CA1 3-1 Guam are reported, and also CA1 3-1 Singapore which has an electrophoretic mobility indistinguishable from that of CA1 3-1 Guam. Included in the tabulations are data on other populations outside the Asian-Pacific area and, for completeness, information already published on variants of both CA1 and CA2. In an effort to simplify the nomenclature of carbonic anhydrase variants, a new system is suggested, using numerals rather than letters to distinguish the variant isozymes. Modifications of the electrophoresis buffer system which enhances the very small mobility differences existing between several of the products of the CA1 alleles are also described.

Malate dehydrogenase types in the Asian-Pacific area, and a description of new phenotypes.

A survey of more than 21 000 haemolysates from blood samples collected in various parts of south and southeast Asia, Australasia and the Western Pacific and examined in this laboratory has revealed several new alleles controlling variants of sMDH; in addition, further information has been provided on the distribution of sMDH3 in New Guinea. Two of the variant alleles, sMDH3 and sMDH6, achieve polymorphic frequency in various populations. sMDH3 is widely distributed in New Guinea, with highest frequencies in the Eastern Highlands. The pattern of its distribution suggests the mutant arose originally in a Papuan-speaking population. So far, sMDH6 has been detected only in Micronesians from a number of islands in the Carolines. A single example of another new variant, sMDH 5-1, and two examples of a slow variant, sMDH 7-1, were detected in samples from Iran and Singapore, respectively. No examples of mMDH variants were found in a total of 652 placental extracts from Papua New Guinea and Australia.

Glutamic pyruvic transaminase and esterase D types in the Asian-Pacific area.

More than 11000 blood samples have been examined for glutamicpyruvic transaminase (GPT) and almost 9000 for Esterase D(EsD) in the Asian-Pacific area; GPT3 and GPT6 were detected in several population groups in New Guinea, Singapore and some Pacific islands. No previously undescribed alleles were found in either system.

Widespread distribution of variant forms of carbonic anhydrase in Australian aboriginals.

Three distinctive genes which control variants of carbonic anhydrase (CA) have been detected in tests on nearly 3000 Aboriginals from various parts of Australia. Two of these genes affect the products of the CA1 locus, the other affects the products of the CA2 locus. In some populations of Aboriginals, more than 10% of persons have a variant carbonic anhydrase. It is suggested that such an unusual frequency of CA variants may be an evolutionary response to metabolic stress connected either with low zinc concentrations in the diet or with the altered needs of ion regulation in an arid environment.

Red cell enzyme and serum protein types in a population from Ndeni (Santa Cruz Islands).

Data for 14 red cell enzyme systems, haemoglobin and four serum proteins are presented for 351 people from the island of Ndeni in the Santa Cruz group of the British Solomon Islands Protectorate. The results support the view based on linguistic studies that the Ndeni population is derived from a mixing of older Papuan and later Austronesian-speaking peoples.

Population genetic studies in the Kimberley of Western Australia.

More than 800 blood samples from members of 13 tribal groups in the northwest of Australia have been tested for 18 enzyme systems controlled by 21 loci and for haemoglobin. Two novel alleles, PGM2(11) and ACP1F, are each restricted to a single tribal population, suggesting relatively recent mutations. Other alleles conform very broadly with their distributions in other Australian Aboriginal populations. In particular, PGM2(3) maintains its inland distribution whilst PGDE and PEP B6 continue to be restricted to the north of the continent. Comparisons between tribes show the Baada to be distinctive, with high values of PGM1(2), GPT2, CA2(4) and ESD2 as well as having the novel allele ACP1F.

A population genetic study of phosphoglycolate phosphatase.

The distribution of phenotypes and the gene frequencies for the enzyme phosphoglycolate phosphatase for more than 3700 individuals from 31 different populations throughout the world are presented.

Phosphoglucomutase types in the Asian-Pacific area: a critical reveiw including new phenotypes.

The distribution of genetic variants at the PGM1 and PGM2 loci in South and East Asia, the Western Pacific and Australasia has been surveyed on the basis of published and unpublished material comprising samples from some 33,000 persons. A critical comparsion of previously described and of new rare alleles at both loci has been undertaken. The present number for PGM1 is 14 and for PGM2 is 12. Many of these have restricted geographic or ethnic distribution.

The frequency of private electrophoretic variants in Australian aborigines and indirect estimates of mutation rate.

The number of "private" electrophoretic variants of enzymes controlled by 25 loci has been used to obtain estimates of mutation rate in Australian Aborigines. Three different methods yield values of 6.11 X 10(-6), 2.78 X 10(-6), and 12.86 X 10(-6)/locus per generation for the total sample of Aborigines. One tribal population of Waljbiri in central Australia gives values of 2.99 X 10(-6) and 2.04 X 10(-6) for two of the methods, the third being unapplicable. The mean mutation rate for the total Aboriginal sample of 7.25 X 10(-6) is very similar to the value obtained by Neel and his colleagues for Amerindians in South America.

Genetic studies on the Kolams of Andhra Pradesh, India.

A total of 220 persons belonging to the Kolam tribe in the Adilabad District of northwest Andhra Pradesh have been tested for 18 red cell eyzyme systems and for haemoglobin. Generally, the gene frequencies for the systems which showed electrophoretic variation were within the range for Indian populations; the gene frequency for AK1 is high by Indian standards and Hb AS is present. LDH Calcutta 1 was not detected in this population and a single example of PHI 2-1 was observed.

Serogenetic studies on the Kamea (Kapau) Anga of the interior of the Gulf Province of Papua.

Though the Anga or Kukukuku of Papua New Guinea have been the subjects of occasional human biological investigations in the past, these have all been directed from the north, and their largest division, the Kamea or Kapau, who occupy the southeastern half of their territory, have been substantially neglected. The present paper describes the results of sero-genetic investigations of a small sample of Kamea, who are shown to resemble their fellow-Anga closely in the distribution of their genetic markers, though there are indications that the Kamea have received some gene flow from the south. On the whole, though, the relative uniformity of gene marker distribution throughout the Anga points strongly to their common origin, and the paucity of signs of immigrant gene flow from their neighbours, the victims of their raids, tends to confirm that they practised cannibalism rather than the genetic incorporation of captives.

Genetic studies on the Savara and Jatapu Tribes of Andhra Pradesh, India.

A total of nearly 300 persons belonging to the Savara and Jatapu tribes in the Srikakulum District of northern Andhra Pradesh have been tested for electrophoretic variation in 13 red cell enzyme systems, and also haemoglobin. The gene frequencies for the systems showing variation are within the range for other South Indian populations, and there are no significant differences between the two tribal groups investigated in this report except in the case of adenylate kinase. The Jatapu (along with the Kadar of Kerala) have the highest frequency of AK1 so far reported in India. Both the Savara and Jatapu showed a low frequency for Hb AS, and LDH-Calcutta 1 was not detected in either population.

Red cell enzyme and serum protein gene markers in Fijians.

A total of 332 persons from three localities in the Fiji Islands have been tested for genetic variation in 24 red cell enzyme systems and 4 serum protein systems. Polymorphic variation was present at 7 red cell enzyme loci and 1 serum protein locus. The remaining systems were invariant except for a single individual with a slow variant at the GOT1 locus and another individual with a D variant at the TF locus. The series from Nandi differed significantly from the Lau Islands for gene frequencies in GPT, ACP and ESD, Koro Island differed from the other localities at the PGD locus and from Nandi for ESD. Genetic distance analysis reveals that Lau Islands cluster with Western Samoa, Koro Island with New Caledonia (Vanuatu), with Nandi being separate.