共查询到20条相似文献,搜索用时 15 毫秒
1.
The variability of Q-heterochromatin regions (Q-HR) was studied in native residents of the northern part of West Siberia, viz Yakuts (n = 127), Selkups (n = 90) and Khants (n = 54), as well as in newcomers including oil-borers (n = 43) and children (n = 113) living permanently in this part of the USSR. The major quantitative characteristics of chromosomal Q-HR variability were shown to be very similar in oil-borers and natives, and this is considered to be the result of specific selection of individuals according to the amount of Q-HRs in their genome. The hypothesis on the possible selective value of chromosomal Q-HRs in human adaptation to extreme environmental conditions of the extreme north is discussed. 相似文献
2.
The variability of human chromosomal Q-heterochromatin regions (Q-HR) was studied in 385 newcomers well adapted to the extreme environmental conditions of Pamir and Tien-Shan, as well as in 284 representatives of the native population of these regions. Newcomers were found to represent a highly homogeneous group as regards all the quantitative characteristics of Q-HR variability, but at the same time they differed significantly from both native residents and individuals of similar nationality (Russians) living permanently at low altitude. Differences between these three groups in the amount of Q-HRs in their genome are discussed as evidence in favour of the hypothesis of the possible selective value of chromosomal Q-heterochromatin material in human adaptation to extreme environmental high-altitude conditions. 相似文献
3.
Novel methods allowing to analyze the human genome make it possible to assess old questions such as the molecular basis of structural chromosome anomalies and the diathesis to aneuploidy. The architecture of the human genome as unravelled by the human genome sequencing project allows to explain the recurrence of microdeletions and microduplications caused by a non allelic homologous recombination involving segmental duplications created during the evolution of primates. This structural feature of the human genome is associated with a novel class of genetic diseases called genomic disorders as opposed to genetic diseases due to gene mutations. The study of the parental and cellular origin of aneuploidy shed new light on the different mechanisms controlling meiosis in man and woman. In addition it contributes to define the role of maternal age and genetic recombination on the behavior of chromosomes during meiosis. These new data greatly contribute to our understanding of human chromosomal diseases. 相似文献
4.
The human insulin resistance syndromes—type 2 diabetes, obesity, combined hyperlipidemia, and essential hypertension—are
genetically complex disorders whose molecular basis is largely unknown. The spontaneously hypertensive rate (SHR) is a model
of these human syndromes. In the SHR/NCrlBR strain, a chromosomal deletion event that occurred at the Cd36 locus during the evolution of this SHR strain has been proposed as a cause of defective insulin action and fatty acid metabolism.
In this study, three copies of the Cd36 gene, one transcribed copy and two pseudogenes, were identified in normal rat strains, but only a single gene in SHR/NCrlBR.
Analysis of SHR genomic sequence localized the chromosomal deletion event between intron 4 of the normally transcribed copy
of the gene and intron 4 of the second pseudogene. The deletion led to the creation of a single chimeric Cd36 gene in SHR/NCrlBR. The boundaries of the recombination/deletion junction identified within intron 4 were surrounded by long
interspersed nuclear elements (LINEs) and DNA topoisomerase I recognition sequences. An 8-bp deletion at the intron 14/exon
15 boundary of the second pseudogene abolishes the putative splice acceptor site and is the cause of an aberrant 3′ UTR previously
observed in SHR/NCrlBR. We conclude that in SHR/NCrlBR, the complex trait of insulin resistance and defective fatty acid metabolism
is caused by Cd36 deficiency, resulting from a chromosomal deletion caused by unequal recombination. This demonstrates that
chromosomal deletions caused by unequal recombination can be a cause of quantitative or complex mammalian phenotypes.
Received: 7 September 2001 / Accepted: 3 October 2001 相似文献
5.
Adam D. Gordon 《International journal of primatology》2006,27(1):27-61
I used a new quantitative genetics model to predict relationships between sex-specific body size and sex-specific relative variability when populations experience differences in relative intensity of sex-specific selection pressures—stronger selection on males or females—and direction of selection: increase or decrease in size. I combined Lande's (Evolution 34: 292–305) model for the response of sex-specific means to selection with a newly derived generalization of Bulmer's (Am. Nat. 105: 201–211) model for the response of relative variability to selection. I used this combined response model to predict correlations of sex-specific size and relative variability under various starting conditions, which one can compare to correlations between closely related primate populations. One can then compare predicted patterns of sex-specific selection pressures to social and ecological variables pertaining to those populations to identify likely forces producing microevolutionary change in sexual size dimorphism (SSD). I provide examples of this approach for populations representing three taxa: Papio anubis, Saguinus mystax, and Cercopithecus aethiops pygerythrus. Model results suggest that microevolutionary changes in SSD can result from greater selection acting on males or females, and that natural selection or natural and sexual selection combined, rather than sexual selection alone, may sometimes explain sex-specific selection differentials. 相似文献
6.
Claudio Tennie Kathrin Greve Heinz Gretscher Josep Call 《Primates; journal of primatology》2010,51(4):337-351
Individuals observing a proficient model can potentially benefit by copying at least one of the following three elements:
motor movements (i.e., actions), goals, and results. Although several studies have investigated this issue in human infants,
there are still very few studies that have systematically examined great apes’ ability to spontaneously copy each of these
three elements (particularly in comparison with human infants). We tested great apes and human children with eight two-target
puzzle boxes—with varying levels of difficulty—to isolate the aspects that the various species may be more prone to copying.
We found first trial evidence for observational learning of actions, goals, and results in children. Some copying was found
for apes as well, but only if their performance was averaged across trials. 相似文献
7.
Paul P.W. van Buul 《Mutation research》1982,95(1):69-77
To evaluate the reliability of quantitative extrapolation of radiation-induced chromosomal damage from somatic cells to germ cells, data on the effects of several biological and physical factors on the chromosomal radiosensitivity of blood lymphocytes and stem-cell spermatogonia have been collected from the literature. The results show that most of the factors considered, such as chromosomal constitution, age, genetic constitution, species, sampling time and dose fractionation, had differential effects on the induction of chromosomal aberrations in both systems. These differential effects can easily be explained in terms of the biological differences between in-vitro-stimulated peripheral blood lymphocytes and stem-cell spermatogonia. It is concluded that only direct experiments on germ cells of higher primates and man can be used for a quantitative estimation of human genetic radiation risks arising from structural chromosomal aberrations. 相似文献
8.
A rhesus macaque radiation hybrid map and comparative analysis with the human genome 总被引:10,自引:0,他引:10
Murphy WJ Agarwala R Schäffer AA Stephens R Smith C Crumpler NJ David VA O'Brien SJ 《Genomics》2005,86(4):383-395
The genomes of nonhuman primates are powerful references for better understanding the recent evolution of the human genome. Here we compare the order of 802 genomic markers mapped in a rhesus macaque (Macaca mulatta) radiation hybrid panel with the human genome, allowing for nearly complete cross-reference to the human genome at an average resolution of 3.5 Mb. At least 23 large-scale chromosomal rearrangements, mostly inversions, are needed to explain the changes in marker order between human and macaque. Analysis of the breakpoints flanking inverted chromosomal segments and estimation of their duplication divergence dates provide additional evidence implicating segmental duplications as a major mechanism of chromosomal rearrangement in recent primate evolution. 相似文献
9.
Comparaison de la structure fine des chromatides d'Homo sapiens et de Pan troglodytes 总被引:1,自引:0,他引:1
Jérôme Lejeune Dr. Bernard Dutrillaux Dr. Marie Odile Rethoré Marguerite Prieur 《Chromosoma》1973,43(4):423-444
Prometaphasic chromosomes of man and chimpanzee are compared, using R, Q, T and H-bands techniques. — Six pericentric inversions, one telomeric fusion-translocation, 4 intercalar deletions or insertions, 16 deletions or additions of terminal Q-bands, and an important variation of heterochromatin distinguish the 2 species. — The evolutive role of chromosomal rearrangements separating the 2 species is discussed with particular reference to the formation of human chromosome No 2.- The simultaneous analysis of human chromosomal pathology and of the chromosomal structures in primates should contribute to the understanding of accidental modifications of the genome and to the interpretation of their consequences.
Travail de l'E.R.A. No 47 du C.N.R.S. 相似文献
Travail de l'E.R.A. No 47 du C.N.R.S. 相似文献
10.
V. Vančata 《Human Evolution》1991,6(1):1-47
Seventy six metrical traits measured on the femur and tibia of three higher primate groups —Ceboidea, Cercopithecoidea, Hominoidea have been processed by various univariate and multivariate statistical methods to survey the process of evolution of the
morphology of the femur and tibia in higher primates. Intragroup and intergroup variability, similarity and differences as
well as various aspects of scaling and sexual dimorphism have been analyzed to study adaptive trends and phylogenetic diversity
in higher primates, in individual superfamilies and to explore the adaptive morphological pattern of early hominids and basic
differences between hominids and pongids. Two basic morphotypes of the femur and tibia in higher primates have been determined.
They are (1) advanced hominoid morphotype (hominids and pongids) and (2) ancestral higher primate morphotype (platyrrhine
and cattarrhine monkeys, early hominoids, and hylobatids). Cebid lower limb bones are adapted to arboreal quadrupedalism with
antipronograde features while femur and tibia of cercopithecid monkeys are basically adapted to the semi-arboreal locomotion.
Early hominoids (Proconsul) and hylobatids are morphologically different from pongids; some features are close toAteles or other monkey species. Pongids and hominids are taken as one major morphological group with different scaling and some
functional and morphological similarities. Numerous analogous features were described on the lower limb skeleton ofPan andPongo showing analogous ecological parameters in their evolution. Major morphological and biomechanical trends are analyzed. It
is argued that early advanced hominoid morphology is ancestral both to the pongids and to early hominids. The progressive
morphological trend in early hominids has been found fromA. afarensis with ancestral hominid morphology, toH. habilis with an elongated femur and structural features similar to advanced hominids. A detailed phylogenetic analysis of higher
primate femur and tibia is also presented. 相似文献
11.
Genomic comparison between apes and humans have made important contributions to our understanding of human evolution. The
modern period of karyological comparisons between humans and other primates began about forty years ago and has been marked
by a series of technical revolutions. In the 1960s pioneering genetic and chromosomal comparisons of human and great apes
suggested, as had Darwin a century before, that our closest relative were the African apes. Early immunological analyses placed
human/apes divergence at about five million year ago. Acceptance of man’s late divergence from the African apes was delayed
by the scarcity of paleontological evidence coupled with a fallacious Asiatic origin hypothesis of the hominoids. Chromosome
banding techniques in the seventies and high resolution methods in the eighties allowed a detailed comparison of the chromosomes
between closely related primates and reinforced the hypothesis of an African origin for humans. It was clearly shown that
humans were more closely related to African apes than to the orang-utan. The last decade has seen a vigorous integration of
molecular and cytogenetic. This powerful combination promises to be quite fruitful because chromosomes can be compared directly
at the DNA level. Fluorescentin situ hybridisation (FISH), chromosome painting, is a colourful technique for establishing chromosomal homology between species.
Results obtained by FISH over the last ten years have resolved the cytogenetic problem of the homology between humans, apes,
hylobates and Old World monkeys and defined the chromosomal syntenies and major translocations involved in the genome evolution
of higher primates. 相似文献
12.
Sluan D. Lin Phil Cooper Jingly Fung Heinz-Ulrich G. Weier Edward M. Rubin 《Mammalian genome》2000,11(11):1024-1029
Genetic factors affecting postnatal γ-globin expression—a major modifier of the severity of both β-thalassemia and sickle
cell anemia—have been difficult to study. This is especially so in mice, an organism lacking a globin gene with an expression
pattern equivalent to that of human γ-globin. To model the human β-cluster in mice, with the goal of screening for loci affecting
human γ-globin expression in vivo, we introduced a human β-globin cluster YAC transgene into the genome of FVB/N mice. The
β-cluster contained a Greek hereditary persistence of fetal hemoglobin (HPFH) γ allele, resulting in postnatal expression
of human γ-globin in transgenic mice. The level of human γ-globin for various F1 hybrids derived from crosses between the FVB/N transgenics and other inbred mouse strains was assessed. The γ-globin level
of the (C3HeB/FeJ × FVB/N)F1 transgenic mice was noted to be significantly elevated. To map genes affecting postnatal γ-globin expression, we performed
a 20-centiMorgan (cM) genome scan of a (C3HeB/FeJ × FVB/N)F1 transgenics × FVB/N backcross, followed by high-resolution marker analysis of promising loci. From this analysis we mapped
a locus within an 18-cM interval of mouse Chromosome (Chr) 1 (LOD = 4.3) that contributes 10.9% of variation in γ-globin level.
Combining transgenic modeling of the human β-globin gene cluster with quantitative trait analysis, we have identified and
mapped a murine locus that impacts on human γ-globin level in vivo.
Received: 26 January, 2000 / Accepted: 2 May 2000 相似文献
13.
A. L. Amosova A. Yu. Komkov S. V. Ustyugova I. Z. Mamedov Yu. B. Lebedev 《Russian Journal of Bioorganic Chemistry》2009,35(6):702-710
The ascertainment of the rates and driving forces of human genome evolution along with the genetic diversity of populations
or separate population groups remains a topical problem of fundamental and applied genomics. According to the results of comparative
analysis, the most numerous human genome structure peculiarities are connected with the distribution of mobile genetic retroelements—LTR,
LINE1, SVA, and Alu repeats. Due to the wide distribution in different genome loci, conversed retropositional activity, and
the retroelements’ regulatory potential, let us regard them as one of the significant evolutionary driving forces and the
source of human genome variability. In the current review, we summarize published data and recent results of our research
aimed at the analysis of the evolutionary impact of the young retroelements group on the function and variability of the human
genome. We examine modern approaches of the polygenomic identification of polymorphic retroelements inserts. Using an original
Internet resource, we analyze special features of the genomic polymorphic inserts of AluY repeats. We thoroughly characterize
the strategy of large-scale functional analysis of polymorphic retroelement inserts. The presented results confirm the hypothesis
of the roles of retroelements as active cis regulatory elements that are able to modulate surrounding genes. 相似文献
14.
Mapping and characterization of seed dormancy QTLs using chromosome segment substitution lines in rice 总被引:1,自引:0,他引:1
Marzougui S Sugimoto K Yamanouchi U Shimono M Hoshino T Hori K Kobayashi M Ishiyama K Yano M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(5):893-902
Seed dormancy—the temporary failure of a viable seed to germinate under favorable conditions—is a complex characteristic influenced
by many genes and environmental factors. To detect the genetic factors associated with seed dormancy in rice, we conducted
a QTL analysis using chromosome segment substitution lines (CSSLs) derived from a cross between Nona Bokra (strong dormancy)
and Koshihikari (weak dormancy). Comparison of the levels of seed dormancy of the CSSLs and their recurrent parent Koshihikari
revealed that two chromosomal regions—on the short arms of chromosomes 1 and 6—were involved in the variation in seed dormancy.
Further genetic analyses using an F2 population derived from crosses between the CSSLs and Koshihikari confirmed the allelic differences and the chromosomal locations
of three putative QTLs: Sdr6 on chromosome 1 and Sdr9 and Sdr10 on chromosome 6. The Nona Bokra alleles of the three QTLs were associated with decreased germination rate. We discuss the
physiological features of the CSSLs and speculate on the possible mechanisms of dormancy in light of the newly detected QTLs. 相似文献
15.
A DNA-library established from microdissected bands 8q23 to 8q24.1 of normal human chromosomes 8 (Lüdecke et al., 1989) was
used as a probe for chromosomal in situ suppression (CISS-) hybridization to metaphase chromosomes of man and primates including
Hylobates lar and Macaca fuscata. Comparative band mapping as first applied in this study shows the specific visualization
of a single subchromosomal region in all three species and thus demonstrates that synteny of the bulk sequences of a specific
human chromosome subregion has been conserved for more than 20 million years. 相似文献
16.
A. S. Kashin 《Russian Journal of Developmental Biology》2012,43(2):101-114
Based on our own and literature data on peculiarities of caryotypical variability, we concluded that gametophytic apomixis
is naturally accompanied with phenomena of poly-, aneu-, and mixoploidy and that apomicts have genome instability manifesting
at the level of meristematic somatic cells. In this connection, a hypothesis is substantiated that realization of this mode
of seed reproduction in flowering plants is caused by modification of systems of cell cycle control, following after acts
of hybridogenesis and/or polyploidization. It is concluded that instability of the seed reproduction system by gametophytic
apomixis manifests not only at the stage of choice of a seed reproduction pathway (apomeiosis—euspory; apozygosis—zygosis)
but also in all the cycles of reproduction of the cells of a germ line in plant ontogenesis. 相似文献
17.
Different degrees of isolation found in various part of Bosnia and Herzegovina may be induced by various factors. Bjelasnica-Treskavica
region, located around 40 kilometers southwest from Sarajevo — capital of Bosnia and Herzegovina, is highly specific in that
way. We chose three isolated communities: Dejcici, Bobovica and Lukomir for the study of genetic structure of isolated human
populations. Based on general data three relative degrees of isolation/openness among the villages have been presumed as follows:
first (lower-Dejcici), second (middle — Bobovica) and third (higher — Lukomir) 15 short tandem repeat (STR) loci and hypervariable
region of mtDNA were chosen as a markers for study of population structure. Microsatellite allele frequencies, and mtDNA molecular
diversity of Heterozigosity and coefficient of gene differentiation across all observed STR loci were estimated. Also, gene
and nucleotide diversity of observed mtDNA regions were obtained. Genetic distance between three populations was calculated
using method of Reynolds et al. (1983). For analysis of interpopulation relationship based on polymorphism of HV I and HV
II region, estimation of pairwise differences was used. results of this research showed consistence with initial hypothesis
on divergence based on socio-cultural factors. 相似文献
18.
Yan G Zhang G Fang X Zhang Y Li C Ling F Cooper DN Li Q Li Y van Gool AJ Du H Chen J Chen R Zhang P Huang Z Thompson JR Meng Y Bai Y Wang J Zhuo M Wang T Huang Y Wei L Li J Wang Z Hu H Yang P Le L Stenson PD Li B Liu X Ball EV An N Huang Q Zhang Y Fan W Zhang X Li Y Wang W Katze MG Su B Nielsen R Yang H Wang J Wang X Wang J 《Nature biotechnology》2011,29(11):1019-1023
The nonhuman primates most commonly used in medical research are from the genus Macaca. To better understand the genetic differences between these animal models, we present high-quality draft genome sequences from two macaque species, the cynomolgus/crab-eating macaque and the Chinese rhesus macaque. Comparison with the previously sequenced Indian rhesus macaque reveals that all three macaques maintain abundant genetic heterogeneity, including millions of single-nucleotide substitutions and many insertions, deletions and gross chromosomal rearrangements. By assessing genetic regions with reduced variability, we identify genes in each macaque species that may have experienced positive selection. Genetic divergence patterns suggest that the cynomolgus macaque genome has been shaped by introgression after hybridization with the Chinese rhesus macaque. Macaque genes display a high degree of sequence similarity with human disease gene orthologs and drug targets. However, we identify several putatively dysfunctional genetic differences between the three macaque species, which may explain functional differences between them previously observed in clinical studies. 相似文献
19.
Exceptional chromosomal variability makesCtenomys an excellent model for evolutionary cytogenetic analysis. Six species belonging to three evolutionary lineages were studied
by means of restriction endonuclease and C-chromosome banding. The resulting banding patterns were used for comparative analysis
of heterochromatin distribution on chromosomes. This combined analysis allowed intra- and inter-specific heterochromatin variability
to be detected, groups of species belonging to different lineages to be characterized, and phylogenetic relationships hypothesized
from other data to be supported. The “ancestral group”,Ctenomys pundti andC. talarum, share three types of heterochromatin, the most abundant of which was also found in C. aff.C. opimus, suggesting that the latter species also belongs to the “ancestral group”. Additionally, within the subspeciesC. t. talarum, putative chromosomal rearrangements distinguishing two of the three chromosomal races were identified. Two species belong
to an “eastern lineage”,C. osvaldoreigi andC. rosendopascuali, and share only one type of heterochromatin homogeneously distributed across their karyotypes.C. latro, the only analyzed species from the “chacoan” lineage, showed three types of heterochromatin, one of them being that which
characterizes the “eastern lineage”.C. aff.C. opimus, because of its low heterochromatin content, is the most primitive karyotype of the genus yet described. The heterochromatin
variability showed by these species, reflecting the evolutionary divergence toward different heterochromatin types, may have
diverged since the origin of the genus. Heterochromatin amplification is proposed as a trend withinCtenomys, occurring independently of chromosomal change in diploid numbers. 相似文献
20.
Luca Morino 《International journal of primatology》2011,32(3):793-800
Many hypotheses have been proposed linking the emergence of lateralized activities—such as handedness—in primates, with hemispheric
specialization and the evolution of complex communication such as human language. Although data to test these ideas are rapidly
accumulating for many primate taxa, some species are still largely unexplored, especially under natural conditions. I present
the first data on a population of wild siamangs (Symphalangus syndactylus), highly arboreal small apes. Preference for the left hand is shown both at the individual and population levels for a complex
manual task: collecting and drinking water from tree holes. There was no difference in hand preference between males and females,
and immature individuals showed more variable patterns than adults. These results are consistent with the postural origins
theory, allow a new interpretation of the findings of comparable studies, and indicate a useful behavior for future investigations
of laterality in wild primates. 相似文献