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PubMed1996

Population structure and genetic differentiation among 16 tribal populations of central India.

Genetic polymorphisms for six blood groups, three red cell enzymes, three serum proteins, and hemoglobin were examined in sixteen central Indian tribal populations. Nine of the tribes belonged to Orissa, five to Madhya Pradesh, and two to Maharashtra. Eleven tribes spoke the Dravidian language, three Indo-Ayran, and two the language of the Austro-Asiatic families. The population structure of these tribal populations was analyzed at the inter- and intrastate and linguistic levels, using data for 13 genetic systems (38 alleles or haplotypes). Nine of the 13 loci showed significant heterogeneity in the 16 tribes, and the pattern of heterogeneity was also discernible in the different states and in the Dravidian-speaking tribes. As expected, the extent of genetic differentiation or gene diversity was the highest so far reported from central India. The mean FIS and HS for each locus in the different state, linguistic, and total tribal groups were consistently higher than the FST and GST values, respectively, showing that the genetic structure of each tribe is highly influenced by inbreeding. In a genetic affinity analysis by genetic distance the Indo-Aryan and Austro-Asiatic language groups showed little affinity with each other, although there was some tendency toward geographic affinity. The present analysis indicates that, in addition to genetic drift, gene flow, and selection, the genetic structure of the populations of central India is also highly influenced by sociocultural adaptation and inbreeding.

Ethnicity↗
PubMed1996

[Genetic structure and the load of hereditary diseases in five populations of Arkhangel'skaia region].

A population and medical genetic investigation was performed in a number of raions in the Arkhangel' skaya oblast. Random inbreeding coefficients were 0.000358 and 0.000361 in the Vinogradovskii and Krasnoborskii raions. Malecot's local inbreeding coefficients were 0.000565 and 0.000472, respectively. The endogamy indices were 0.37 and 0.54, respectively. In the urban population, the loads of autosomal dominant, autosomal recessive, and X-linked pathology were 1.01 and 0.98 per 1000 individuals, and 0.29 per 1000 men; in the rural population, they were 1.22, 1.55, and 1.08, respectively. In the populations studied, the hereditary pathology spectrum is described.

Consanguinity↗
PubMed1996

[Induction of transposition and excision of mobile genetic elements in Drosophila during isogenization].

Localization patterns of mobile genetic element (MGE) Dm412 were compared in chromosomes of ten isogenic lines and a heterogeneous control line riC of Drosophila. Isogenization was shown to induce MGE transpositions and excisions. Rates of induced transpositions and excisions were, respectively, 0.35 and 0.13 per site per haploid genome per isogenization, which is significantly (by two to three orders of magnitude) higher than corresponding rates in the control line. These values are also higher by an order of magnitude than previously obtained rates of transposition induction by means of heat shock treatment and gamma-irradiation of isogenic lines. In the average haploid genome of the original line, nc = 22.14 of the occupied Dm412 sites correspond to 11.9 transpositions and 4.6 excisions generated by isogenization. Calculated for the genomic system of copia-like MGE, these rates are approximately 105 and 39 events per approximately 300 initial MGE positions. Apparently, these rates exceed the "catastrophic limit of transpositions and excisions." A hypothesis on the role of inbreeding as genomic stress in induction of transpositions and excisions was proposed. Inbreeding is assumed to increase cell concentration of defective proteins, acting via the system of heat shock response-a general system of cell response to external and physiological stresses.

Animals↗
PubMed1997

Spontaneous pathology of the gray short-tailed opossum (Monodelphis domestica).

The gray short-tailed opossum, Monodelphis domestica, is a newly established laboratory animal that is becoming increasingly important to biomedical research. Because little disease information is available for this species, we reviewed records for spontaneous gross and histologic lesions and microbiologic results in 150 M. domestica necropsies during an 11-year period. We identified 150 (91 female, 59 male) animals from 441 necropsy cases which were controls in experimental protocols or were members of the breeding colony. Initial statistical examinations indicated that the sample was representative of the living members of the breeding colony with respect to age, sex, and range of inbreeding. Causes of death and types of tumors were specifically evaluated. Females died earlier than males (22.6 +/- 13.0 months versus 30.9 +/- 11.9 months), but this difference was not associated readily with diet or inbreeding levels. The organ systems with the greatest lesion prevalences, in decreasing order, were the digestive, urogenital, cardiovascular, and respiratory systems. The most probable causes of all deaths were associated with the digestive system, followed by the cardiovascular and integumentary systems. The principal disease problems were rectal prolapse, congestive heart failure, and dermatitis. Neoplasia was found in 39 of the animals. The prevalence of neoplasia was greatest in the digestive system, followed by the endocrine, urogenital, integumentary, and hematopoietic systems. Pituitary adenoma was the most common neoplasm, followed by uterine leiomyoma and cutaneous lipoma. Specific microbially-induced diseases were not recognized, and endo- and ectoparasites were not found in colony-born M. domestica.

Animal Diseases↗
PubMed1997

[Population-demographic structure in the Kurskaya district. Isolation by distance].

The population of the Kurskaya oblast (administrative region) was described using the Malecot's model of isolation by distance. Differences in inbreeding level between populations of raions (districts) were found; the differences were determined by degrees of urbanization, age, and effective size of the populations. In the center of the oblast, an area was found with the minimum mean square distance between birthplaces of spouses, low effective migration pressure, and high isolation by distance. In populations of raions, a relationship was found between population inbreeding level and incidences of congenital malformations (CM) and multiple congenital malformations (MCM), which affected the viability of infants.

Abnormalities, Multiple↗
PubMed1997

[Genetic polymorphism in three indigenous ethnic populations of Dagestan].

Genetic, demographic, and biochemical studies of three isolated ethnic populations of Dagestan were performed. Two populations lived in their historical (highland and lowland) habitats, and one population migrated from highlands to lowlands, i.e., changed its environment. A substantial genetic differentiation with respect to eight biochemical systems and marital structure was found. Altitudinal variation was revealed in allelic frequencies of group-specific component (GC) and haptoglobin (HP). The frequency of allele GC * 1 decreased and that of allele HP * 1 increased as the altitude increased in the studied localities. The studied populations differed with respect to the average heterozygosity levels per locus. Both absolute heterozygosity levels and the pattern of interpopulation differences estimated for all of the eight biochemical markers considerably differed from those estimated for all markers except for GC and HP. These data indicate that the latter two biochemical systems are important for adaptation of the studied Dagestan populations. In surviving migrants from highlands to lowlands, the levels of inbreeding and genetic polymorphism were intermediate between these values for highlanders and native lowlanders. Earlier, the 30% selective mortality was revealed in migrants from highlands to lowlands during the first years of adaptation to new conditions. Those individuals who died had a higher inbreeding level, homozygosity, and physiological sensitivity. In this study, only surviving migrants were examined. Therefore, it may be suggested that the inadaptive (dying) part of migrants also differed from the adaptive (surviving) part in the higher HP * 1 and GC * 2 allelic frequencies.

Alleles↗
PubMed1998

Multiple kinship in two Spanish regions: new model relating multiple and simple consanguinity.

The structure of the different categories of multiple consanguineous marriages (MCMs) and their historical variation patterns are analyzed in the Spanish dioceses of Alava (Basque Country) and Sigüenza-Guadalajara (Castile). Consanguineous marriages, up to third cousins, were taken from ecclesiastical dispensations, and the periods studied were 1831-1980 for Alava and 1861-1980 for Sigüenza-Guadalajara. Significant differences exist in the MCM rates in the two Spanish areas. In this study a model is proposed to prove that in a general population there may be dependence between MCM rates for specific relationships and the frequencies of those types of relationships in the form of simple consanguineous marriages (SCMs). The effects of avoidance and preferentiality and of underreporting are discussed to explain the deviations between observed and expected consanguineous marriage frequencies. A limit to the weight of remote consanguinity on the population inbreeding coefficient F is determined. The relationship between FT/FS and ms values from our two Spanish populations are fitted to curvilinear regressions. FT is the total population inbreeding coefficient, FS is the contribution to FT from SCMs, and ms is the relative observed frequency of SCMs in the general population.

Cohort Studies↗
PubMed1978

[Mental capacity and human consanguinity].

Mental abilities and inbreeding. The comparison between 1,302 adults born from consanguineous marriages underlines a heavy depression of mental abilities. The load of inbreeding equals the load of environment, both adding their influences, without interaction. Homozygosity acts probably more particularly on the brain.

Consanguinity↗
PubMed1998

Surnames and genetic structure of a high-altitude Quechua community from the Ichu River Valley, Peruvian Central Andes, 1825-1914.

Changes in isolation, inbreeding, population subdivision, and isonymous relationships are examined in six Quechua communities from the upper valley of the Ichu River in the Peruvian Central Andes (3700 m). All marriages registered between 1825 and 1914 in the Parish of Santa Ana were analyzed. The data (1680 marriages) were divided into 2 periods (1825-1870 and 1871-1914) and into the 6 villages that constitute the parish. Endogamy rates are between 81% and 100%, indicating high levels of reproductive isolation. The inbreeding indicated by isonymy (Ft, Fr, and Fn) is lower than in other mountain populations studied. Isonymy values, calculated from the different surname combinations made possible by the Ibero-American Surnames System, indicate a strong rejection of consanguineous marriages, particularly between patrilineal relatives, in agreement with the parental structure typical of Andean populations. The comparison between observed and expected repeated-pair values reveals a moderate level of subdivision within populations, which could be related to cultural and socioeconomic factors. Nonmetric multidimensional scaling was used to investigate temporal changes in the isonymous relationships among the communities. The results reveal a decrease in the interpopulational variability measured by surnames, in agreement with an increase in exogamy. Surnames and data contained in historical and demographic records yield reliable information, and they can be used to reconstruct the biological history of Amerindian populations over the last few centuries.

Analysis of Variance↗
PubMed1979

Familial anthropophobia in pointer dogs?

This article assesses a dog model in terms of a proposed cross-species definition of phobia, the model referring to a strain of unstable dogs that has been produced by selection and inbreeding. The unstable dogs are contrasted with a strain of stable dogs. New findings are presented on approach and activity behavior toward three stimulus objects (man, another dog, and a sheet-covered chair) in a naturalistic setting. The fear response of unstable dogs to objects other than man habituates gradually, whereas the fear response to the sight of man is far more enduring, suggesting a relatively specific fear of man.

Animals↗
PubMed1999

Female mating strategy in an enclosed group of Japanese macaques.

Female Japanese macaques (Macaca fuscata) are noted for mating with multiple males and for their ability to exert mate choice. In a captive group of Japanese macaques housed at the Primate Research Institute of Kyoto University, Japan, behavioral and endocrine data were combined to examine female mating strategies. During one breeding season, daily behavioral observations were conducted on females who exhibited copulatory behavior. Blood was collected from females twice weekly and their ovulatory periods estimated by analyzing hormone profiles. Females began mating shortly before ovulation, peaked at ovulation, and continued receiving ejaculations for up to ten weeks after conception. Females were more responsible than males for inbreeding avoidance with matrilineal kin. Males sometimes approached females from their own matriline, but females avoided such males and expressed mate choice behavior preferentially toward non-matrilineal males. Over the entire mating season, females did not choose non-matrilineal males on the basis of displays, dominance rank, age, weight, or weight change during the mating season. When females were likely to conceive, however, they expressed mate choice behavior toward males who displayed most frequently. Female mating strategy may include both mate choice at ovulation and other, non-procreative functions.

Animals↗
PubMed1988

Dandy-Walker malformation in Ellis-van Creveld syndrome.

We report on 2 Old Order Amish patients with Ellis-van Creveld (EvC) syndrome and the Dandy-Walker malformation; a similar case is noted in the literature. Pedigree analysis of our patients documents extensive inbreeding in successive generations. Considering the rarity of EvC syndrome and Dandy-Walker malformation as isolated malformations, the appearance of both in our 2 patients plus the patient in the literature suggests that Dandy-Walker malformation may be a manifestation in the EvC syndrome. However, in this isolate the coincidental occurrence of 2 rare recessive traits cannot be excluded.

Dandy-Walker Syndrome↗
PubMed1988

Founder effect and genetic disease in Sottunga, Finland.

Pedigree data are analyzed in order to determine the factors responsible for the high frequencies of certain genetic disorders in an isolated Swedish-speaking population of Finland's A land archipelago. The founders of Sottunga are identified, and the genetic contributions of each founder to descending birth cohorts are estimated. Founders born before 1700 have far more descendants in the contemporary gene pool than do more recent founders. However, because of migration and depopulation since 1900, the expected genetic contributions of the early founders to the present-day population are similar to those of later founders. A descendant in the contemporary population has a 2% chance of having inherited a particular gene from the founder who makes the largest single contribution to the gene pool. This corresponds approximately to a 2% probability of inheriting an autosomal dominant disease gene from this founder. Given an average inbreeding coefficient of 0.0016, the probability of inheriting two recessive disease genes from this founder is 0.000032. The incidence of autosomal dominant von Willebrand disease in Sottunga is greater than 10% while that of autosomal recessive tapetoretinal disease is 1.5%. We conclude, therefore, that the high frequencies of these diseases are not due to the disproportionate genetic contribution of one or a few particular founders. It is more likely that these disease genes occurred in high frequency in the initial population or were introduced repeatedly through time.

Finland↗
PubMed1995

DNA fingerprinting to determine paternity in laboratory rat sperm competition experiments.

Prior to this study a significant amount of research had been undertaken in the field of sperm competition in mammals. However, males of different strains have been required in each of these studies to enable paternity assignment through gene expression, which has consequently resulted in problems with differential fertilising capacity being encountered. In this study paternity assignment of progeny from sperm competition experiments with Sprague Dawley rats was achieved by multilocus DNA fingerprinting using band locus matching of individual specific banding patterns between progeny and parents. Trials with 4 restriction enzymes and 5 digoxygenin labelled probes (4 oligonucleotide and 1 cloned) achieved the highest levels of DNA fingerprint heterozygosity using AluI(CAC)5 and HinfI(CAC)5 combinations; however, paternity could not be determined in all offspring, due to a higher than expected degree of inbreeding within the rat population used in this study. This was demonstrated in subsequent comparisons of genetic diversity of three laboratory rat breeding populations from two different animal breeding facilities. Data from the rat mating study showed that, under conditions of direct sperm competition, second males given access to a mated oestrus female either 0.5 or 6.0 h after the first mating consistently required less time than the first to ejaculate: 7.6 min vs. 19.5 min (0.5 h delay ); 7.8 min vs. 19.5 min (6.0 h delay). A second males siring advantage was identified using DNA fingerprinting in both delay groups for those offspring on which paternity could be determined: 0.5 h delay, 1st = 39%, 2nd = 61%; 6 h delay, 1st = 34%, 2nd = 66%.

Animals↗
PubMed1995

Genetic self-management in a captive colony of mandrills (Mandrillus sphinx) as revealed by DNA minisatellite fingerprints.

DNA fingerprints using three oligonucleotide probes, a (GTG)5 short tandem repeat sequence, and 2 corresponding to the core sequences of minisatellites 33.15 and 33.6, have been used to generate DNA fingerprints of a captive colony of mandrills (Mandrillus sphinx) housed at the Centre International de Recherches Médicales de Franceville (CIRMF), in order to monitor paternity. A colony of 6 males and 7 females was established in a 6 ha. rain-forested enclosure in 1983. Band sharing scores indicated that none of the founders were related. By April 1994 the colony had increased to 84 individuals. Forty-nine of the 77 births were first-generation infants, a further 27 were second-generation offspring, and one was a third-generation mandrill. Five animals died during the study, and one was removed for husbandry reasons. Overall band sharing between individuals increased markedly and the power to discriminate between first- and second-generation infants was reduced; the probability of two individuals sharing the same pattern increased 1000-fold from 10(-6) to 10(-3). The dominant male in the group effectively guards access to all receptive females during the annual breeding season. Paternity analysis confirmed that the dominant male is the father of the great majority of offspring born during this term of dominance. Daughters born before 1991 to either of the two dominant males reached sexual maturity during this tenure. Incestual inbreeding occurred with both males, but only 25% of all possible cases resulted in the birth of a viable infant; one male fathered infants on 3 of 13 possible occasions and a second male on 2 of 7 occasions. Female avoidance strategies and shifts in male dominance in this closed mandrill colony appeared to be timed in a way that reduces incest.

Animals↗
PubMed1975

Gentics of urogenital abnormalities in ACI inbread rats.

The frequency of urogenital abnormalities in adult ACI rats was 18.8%. These abnormalities consisted of a spectrum of defects ranging from focal aplasia of the ureter to the complete absence of the ureter, kidney, and tubular genital tract on the affected side. When ACI rats with normal urogenital tracts tracts were crossed with F344 rats the frequency of the defects decreased to a constant level in the F1, F2, and F3 generations. There was no clearly significant decrease in the frequency of the defects in the backcross offspring of (ACI times F344)F1 times ACI matings, but there was a significant and dramatic decrease in the backcross to F344 rats. Attempts to select against these defects by brother-sister matings among normal ACI rats were not successful: 5 generations of inbreeding did not alter the frequency of the urogenital abnormalities. The frequency of the abnormalities was the same in the offspring of affected parents as in the offspring of normal parents, indicating homozygosity of the factors responsible for the defects. The results suggest that the transmission of these defects is polygenic.

Animals↗
PubMed1978

An anatomic and genetic study of canine cryptorchidism.

Twelve cases of cryptorchidism were found in a colony of Minature Schnauzer purebred and crossbred dogs. At least nine affected dogs were derived from the same sire directly or indirectly. Of 12 affected dogs, five cases were unilateral and seven were bilateral. Eight of the 12 cases were subjected to anatomic study. Fixation of affected organs was by vascular perfusion or immersion. Testes were separated from epididymides and both were weighed. All unilateral retained testicles were on the right side, and right sided bilaterally retained testes were always smaller than their left sided counterparts. With only one exception, ectopic testes were in the abdominal positon. Developmentally, the morphologic appearance of the epididymis of abdominal testes was very primitive in bilateral cases but nearly normal in the unilateral cases. Degree of inbreeding was greater for bilateral cases than unilateral cases. High incidence of cryptorchidism in this colony provided good evidence for hereditary nature of the condition in the Miniature Schnauzer dog. Morphologic observations were suggestive of a multiple gene defect.

Animals↗