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PubMed2006

[From population genetics to population genomics of forest trees: integrated population genomics approach].

Early works by Altukhov and his associates on pine and spruce laid the foundation for Russian population genetic studies on tree species with the use of molecular genetic markers. In recent years, these species have become especially popular as nontraditional eukaryotic models for population and evolutionary genomic research. Tree species with large, cross-pollinating native populations, high genetic and phenotypic variation, growing in diverse environments and affected by environmental changes during hundreds of years of their individual development, are an ideal model for studying the molecular genetic basis of adaptation. The great advance in this field is due to the rapid development of population genomics in the last few years. In the broad sense, population genomics is a novel, fast-developing discipline, combining traditional population genetic approaches with the genomic level of analysis. Thousands of genes with known function and sometimes known genomic localization can be simultaneously studied in many individuals. This opens new prospects for obtaining statistical estimates for a great number of genes and segregating elements. Mating system, gene exchange, reproductive population size, population disequilibrium, interaction among populations, and many other traditional problems of population genetics can be now studied using data on variation in many genes. Moreover, population genomic analysis allows one to distinguish factors that affect individual genes, alleles, or nucleotides (such as, for example, natural selection) from factors affecting the entire genome (e.g., demography). This paper presents a brief review of traditional methods of studying genetic variation in forest tree species and introduces a new, integrated population genomics approach. The main stages of the latter are : (1) selection of genes, which are tentatively involved in variation of adaptive traits, by means of a detailed examination of the regulation and the expression of individual genes and genotypes, with subsequent determination of their complete allelic composition by direct nucleotide sequencing; (2) examination of the phenotypic effects of individual alleles by, e.g., association mapping; and (3) determining the frequencies of the selected alleles in natural population for identification of the adaptive variation pattern in the heterogeneous environment. Through decoding the phenotypic effects of individual alleles and identification of adaptive variation patterns at the population level, population genomics in the future will serve as a very helpful, efficient, and economical tool, essential for developing a correct strategy for conserving and increasing forests and other commercially valuable plant and animal species.

Adaptation, Physiological↗
PubMed2006

Dominance, submissivity (and homosexuality) in general population: testing of evolutionary hypothesis of sadomasochism by Internet-trap-method.

OBJECTIVES: Dominance and submissiveness represent strong sexual arousal stimuli for a considerable part of population. In contrast to men's sexual dominance and women's sexual submissiveness, the opposite preferences represent an evolutionary enigma. Here, we studied prevalence and strength of particular preferences in general population by Internet-trap-method. DESIGN: The subjects who clicked the banner displayed in the web interface of e-mail boxes were allowed to choose icons with homosexual or heterosexual partner of different hierarchical position. RESULTS: Dominant partner was chosen by 13.8% men and 20.5% women, and submissive partner by 36.6% men and 19.8% women. Homosexual partners were chosen by 7.3% men and 12.2% women. The response times for the submissive and dominant stimuli did not differ while for the equal-status stimuli were significantly longer, suggesting that part of subjects with equal-status preferences probably intentionally mask their natural interests. CONCLUSIONS: Large number of people who chose unequal sexual partner suggests that hierarchical status plays important role in human mating system.

Biological Evolution↗
PubMed1991

BB/O(ttawa)K(arlsburg) rats: features of a subline of diabetes-prone BB rats.

The development of incidence and age at onset of diabetes as well as the breeding performance and other phenotypic traits of the BB/O(ttawa)K(arlsburg) rat subline are assessed in relation to degree of inbreeding and mating system. With increasing inbreeding body weight decreased and striking changes were observed in incidence and age at onset of diabetes, whereas breeding performance remained largely unchanged. Because the rats were free of most of the relevant pathogens and the transfer of BB rats into a germ-poor environment with the aid of wet hysterectomy had no effect on incidence and age at onset of diabetes, a segregation of diabetogenic genes rather than an influence of environmental factors is supposed to be responsible for both the varying traits.

Aging↗
PubMed1988

Inhibition of plasmid conjugation by some recently synthetized 4-quinolone compounds.

Four fluoroquinolones (norfloxacin, ciprofloxacin, ofloxacin, and pefloxacin) were compared with nalidixic acid for their inhibitory effect on conjugal plasmid transfer. The inhibition was observed in mating experiments using various combinations of drugs at subinhibitory concentrations and 3 different plasmids in the E. coli k12 genetic background. Fluoroquinolones inhibited plasmid transfer to a greater extent than nalidixic acid. Ofloxacin and pefloxacin were consistently the most active agents, causing 90 to 100% inhibition of plasmid transfer in all mating systems studied.

Anti-Infective Agents↗
PubMed1987

Transfer of the heritable nonhemolytic jaundice trait from the Gunn rat to the Sprague-Dawley rat.

Congenital nonhemolytic jaundice as observed in the Gunn rat was transferred successfully to the Sprague-Dawley rat. This jaundice trait occurs as the result of a deficiency of bilirubin glucuronyltransferase and appeared to transfer by simple Mendelian inheritance. A comparison of jaundiced Gunn with jaundiced Gunn-Sprague-Dawley cross rats for plasma bilirubin level, bilirubin glucuronyltransferase activity and female reproductive performance showed no significant difference between the two jaundiced rat groups. The phenotypic expression of the jaundice trait as viewed by the parameters used in this study appeared to be the same for both the Gunn and Gunn-Sprague-Dawley cross rats. The transfer of the jaundice trait to another rat strain enhances the opportunity to characterize this animal model and to determine the possible influence of a long-term closed mating system.

Animals↗
PubMed1987

Male-female interactions across the female estrous cycle: a comparison of two species of dwarf hamster (Phodopus campbelli and Phodopus sungorus).

Recent studies in our laboratory have suggested that monogamy may be the preferred mating system in the Djungarian hamster (Phodopus campbelli), whereas the available evidence for the closely related Siberian hamster (P. sungorus) does not show the same pattern. Here we examine the behavior of male-female dyads of both species interacting during 1-hr tests in large, familiar habitats containing defensible nest boxes, food, and water. Levels of aggression within pairs were low, compared with those seen during brief intrasexual encounters, whereas affiliative behaviors, such as sniffs, were high. P. campbelli scent marked more than twice as frequently as P. sungorus. Females of both species scent marked at a constant rate irrespective of their location in the habitat, whereas males scent marked at a higher rate in the female's home area. Two major features of the copulatory pattern differed between the two species: (a) The duration of the ejaculatory lock was five times longer in P. sungorus than in P. campbelli. (b) Both species had approximately the same number of mounts in each ejaculatory series, but the intromission/mount ratio was significantly higher in P. sungorus.

Agonistic Behavior↗
PubMed1979

[Acceptance and transfer of plasmid Rts1 by bacteria of the genus Erwinia].

The ability of 13 Erwinia strains to accept, to inherit and to transmit the Rts1 factor by conjugation was studied. 11 strains accepted the Rts1 factor from Escherichia coli K-12 CSH-2 with the frequency of about 10(-7)--10(-3). The Rts1 factor was genetically stable in the Erwinia cells and was not eliminated by acriflavine and under the temperature of 37 and 42 degrees C. All the R+ exconjugants were characterized with more high degree of the resistance of kanamycin than E. coli cells harbouring the same R factor. Erwinia strains harbouring the Rts1 plasmid transferred it by conjugation into homologic (Erwinia) and heterologic (E. coli) bacteria. The study of kinetics of the transfer of the Rts1 factor in different mating systems showed that the transfer of this plasmid from R+ Erwinia into R- Erwinia and R- E. coli--in the liquid medium. It is concluded that Erwinia can be the host and the donor of the Rts1 factor.

Conjugation, Genetic↗
PubMed1980

Reproduction in wild gorillas and some comparisons with chimpanzees.

Information was collected over a period of almost 12 years on the gorillas of the Virunga Volcanoes region of Rwanda and Zaire, most of it collected since September 1972. Comparisons were made with the Gombe Stream chimpanzee population (values in parentheses). Gorilla females matured at about 8 years (compared with 9-10 years for the chimpanzee) and first bred at 10-11 years (11-12 years). Males started to breed later, possibly at 15 years (about 13 years). Oestrous periods of female gorillas lasted for about 2 days (10 days) and oestrous cycles for about 30 days (36 days). Gestation in the gorilla lasts 255 days (228 days). Intervals between surviving offspring in the Virunga study groups was about 4 1/2 (5 1/2 years) but in the whole Virunga population was nearer 8 years. Lactational amenorrhoea lasted about 2 1/2 years (3 1/2 years). In gorillas and chimpanzees there were about 3 cycles to conception after parturition and females probably produce in their lifetime about 3 offspring that survive to adulthood. A successful male's productivity is greater. Mortality of immature gorillas was about 40% (50%). Initiation of courtship is generally by the female in gorillas but the male in chimpanzees. Copulation in gorillas lasts for about 1 1/2 min (7 sec) and occurs at a rate of once every 3 h when a female is in oestrus (once in 2 h). Interference in copulation is more common in the chimpanzee than the gorilla, but competition between individual males is more intense in gorilla populations. Females of both species can clearly exercise their preferences for particular males. The observed differences between the species in courtship and mating behaviour can be related to differences in the number of males available to and competing for oestrous females: in the loose multi-male chimpanzee community there is more advantage to males in initiating copulation and mating frequently and efficiently, and to females in advertising oestrus, than in the relatively stable one-male mating system of the gorilla.

Animals↗
PubMed1982

The least shrew (Cryptotis parva) as a laboratory animal.

Wild least shrews, Cryptotis parva, have been maintained in the laboratory for 15 years. Animals were confined in small, open terraria with loam soil covering the floor. The shrews were fed mealworms and a mixture of ground meat and mink diet twice daily. Heterosexual pairing was the mating system most commonly employed. The gestation period was 21 to 22 days, and the mean litter size was 4.3 with a range of 1-9 offspring. The young were weaned at 18-20 days of age and were sexually mature prior to the age of 40 days. Periodontal disease was the only disease which threatened the colony, and it was controlled by adding oxytetracycline hydrochloride to the water. Maximum laboratory survival time was 889 days.

Animal Husbandry↗
PubMed1980

Establishment of a cynomolgus monkey (Macaca fascicularis) breeding colony in Malaysia: a feasibility study.

A breeding colony utilizing a harem mating system was established to study the feasibility of breeding cynomoglus monkeys, Macaca fascicularis, in Malaysia. Two groups consisting of 10 females and one male each were evaluated over a 3 period. Forty births were recorded; one was stillborn, 11 died while nursing, and 28 were weaned. The average time to wean offspring was 230 days with an average weight at weaning of 0.858 kg. The average time for conception to take place after weaning was 50 days. Of the 20 breeder females, six produced three offspring each, nine produced two offspring each, four produced one offspring each and one remained barren throughout the project. Three different weaning systems were evaluated. The best method was caging the mother-infant pair within or adjacent to the breeding room followed by a two-part cage system which allowed the infant to continue nursing and also obtain solid food inaccessible to the mother.

Animals↗
PubMed1995

Introduction of flocculation into industrial yeast, Saccharomyces cerevisiae saké, by protoplast fusion.

Protoplast fusion was applied to obtain intraspecific fusion in yeast strains in order to overcome restrictions imposed by the natural mating system. Acriflavine was used to construct petite mutants from non-flocculent industrial Saccharomyces cerevisiae saké strain. UV radiation was used to construct ura- mutants from a respiratory competent and highly flocculent S. cerevisiae NCYC869 strain. Fusion products were selected by complementation on minimal medium. The frequency of appearance of prototrophic hybrids was five per 10(5) protoplasts. The stable hybrids showed not only the S. cerevisiae saké characteristics but also flocculation ability, thereby confirming the success of the fusion.

Cell Fusion↗
PubMed1994

Management, breeding, and reproductive performance of pine voles.

Pine voles (Microtus pinetorum) serve as an interesting rodent model for studies of fossorial adaptation and mammalian mating systems. They are unusual among rodents in displaying a cooperative system of breeding. Here we describe the management of a breeding colony of pine voles. This species is relatively easy to maintain in the laboratory, although care must be taken to provide sufficient water in their diet. Details of reproduction, as well as growth and development of the young, are included. Pine voles have a smaller litter size (2.3 +/- 0.9 pups at birth) than do other arvicoline rodents but are still prolific breeders, producing, on average, a litter per month for more than 12 months. These rodents are useful for comparison with other arvicoline rodents, as well as providing an opportunity to investigate the behavior, physiology, and reproduction of an easily managed cooperatively breeding mammal.

Aging↗
PubMed1994

[Androcentric attitude in anthropology: examples from research of the evolution of man].

While feminist anthropology already gained a certain tradition in the USA, there are almost no corresponding approaches in the German-speaking sphere. Comparing male viewpoints, which still prevail in science, with female perspectives reveals that a male bias frequently caused misinterpretation, especially in the field of human evolution. Using the topics hunter/gatherer, concealment of ovulation, and mating systems as examples, male and female perspectives are compared. These examples reveal the existence of differences between male and female points of view, and they show how female perspectives complement scientific findings and improve the precision of descriptions. Therefore interpretations from a female point of view should increasingly be considered, in order to gain further insights and improve the formation of hypotheses in the field of human evolution and behavior.

Anthropology, Cultural↗
PubMed1996

Distribution of chewing lice upon the polygynous peacock Pavo cristatus.

An opportunistic survey of louse distribution upon the peacock Pavo cristatus was undertaken following a cull of 23 birds from an English zoo. After complete skin and feather dissolution, 2 species of lice were retrieved, Goniodes pavonis and Amyrsidea minuta. The distribution of both louse species could be described by a negative binomial model. The significance of this is discussed in relation to transmission dynamics of lice in the atypical avian mating system found in the peacock, which involves no male parental care.

Animals↗
PubMed1996

The influence of hunting pressure on the social behavior of vertebrates.

The study of the influence of human hunting pressure on the social behavior of vertebrates requires a large background on both the hunting pressure and the social behavior of the species. Literature about this subject is relatively scarce. Most of the papers are restricted to shifts in demography, and are generally "species-specific". However, human hunting pressure can not only affect demography but also some factors of the social behavior of a species such as parental care, territoriality, reproductive behavior, group-size, fraying behavior, mating system, and intraspecific competition. The presence of hunters in the area can lead the animals to move out of their original home-rangers. This can breakup the social structure and can cause long-term effects on the demography of hunted as well as nearby populations, amplifying the impact of hunting. On the other hand, harvest can be compensated in territorial species by "surplus population" of non-territorial individuals. Moreover, alternatively, an increase in the reproductive activity, as a response to hunting pressure, can compensate its effects in some species. Understanding the implications of hunting pressure in the social behavior of vertebrates might be decisive to the establishment of wildlife management and conservation programs. Manipulative experiments might help us to model such complex interactions. The occurrence of qualitative and quantitative changes in vertebrate social behavior directly or indirectly related to human hunting pressure is reviewed and analyzed in this paper.

Animals↗
PubMed1996

[Immigration of a pregnant female in an alpine marmot family group: behavioural and genetic data].

The acceptance of a pregnant female by the dominant male of a family group of alpine marmots (Marmota marmota) (population of La Grande Sassière, Parc national de la Vanoise, French Alps) was revealed by the combined results from microsatellite polymorphism analysis and behavioural studies. These first results seem to indicate that the mating system of the alpine marmot is more complex than previously thought, that polygyny cannot be excluded, and that adult females can join neighbouring groups. This acceptance would have been interpreted as an extra-pair fertilization if complete field data had not been available.

Animals↗
PubMed2005

The mating pair formation system of conjugative plasmids-A versatile secretion machinery for transfer of proteins and DNA.

The mating pair formation (Mpf) system functions as a secretion machinery for intercellular DNA transfer during bacterial conjugation. The components of the Mpf system, comprising a minimal set of 10 conserved proteins, form a membrane-spanning protein complex and a surface-exposed sex pilus, which both serve to establish intimate physical contacts with a recipient bacterium. To function as a DNA secretion apparatus the Mpf complex additionally requires the coupling protein (CP). The CP interacts with the DNA substrate and couples it to the secretion pore formed by the Mpf system. Mpf/CP conjugation systems belong to the family of type IV secretion systems (T4SS), which also includes DNA-uptake and -release systems, as well as effector protein translocation systems of bacterial pathogens such as Agrobacterium tumefaciens (VirB/VirD4) and Helicobacter pylori (Cag). The increased efforts to unravel the molecular mechanisms of type IV secretion have largely advanced our current understanding of the Mpf/CP system of bacterial conjugation systems. It has become apparent that proteins coupled to DNA rather than DNA itself are the actively transported substrates during bacterial conjugation. We here present a unified and updated view of the functioning and the molecular architecture of the Mpf/CP machinery.

Antigens, Bacterial↗
PubMed2000

A conserved location for the central nervous system control of mating behaviour in gastropod molluscs: evidence from a terrestrial snail.

We have investigated the role of the right mesocerebrum in the expression of mating behaviour in the garden snail Helix aspersa. Using an in vivo stimulation and recording technique, we provide evidence for both sensory and motor functions in the mesocerebral neuronal population. Some neurones were specifically sensitive to tactile stimuli delivered to the skin on the superior tentacles and around the genital pore. Electrical stimulation of the right mesocerebrum evoked genital eversion and, in combination with tactile stimulation, dart-shooting and penial eversion. Genital eversions were also elicited by injections of APGWamide. During courtship, one recorded unit increased its activity only in correlation with penial eversion, while six other units increased their activity only during dart-shooting. Three additional units increased their activity during both types of behaviour. In addition, most of the recorded units showed increased neuronal activity during times of contact with a partner. Comparison of our results with available data from other molluscs leads us to conclude that the right anteromedial region of the cerebral ganglion is an evolutionarily conserved region of the gastropod brain specialised for the control of male mating behaviour. It is striking to find such functional conservation in the central nervous system of phylogenetically distant gastropods given the large differences in behaviour during mating.

Animals↗