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2. Body size and mating success in Pyrrhocoris apterus (Heteroptera)
- Creator:
- Honěk, Alois
- Type:
- article, model:article, and TEXT
- Subject:
- Pyrrhocoris apterus, males, females, sex ratio, copulation, assortative mating, mating duration, population density, and group size
- Language:
- English
- Description:
- The effects of body size on mating success and duration of copulation were investigated in Pyrrhocoris apterus. Under laboratory conditions relative mating success of small and large males was investigated in groups of 2 males (majority sex) : 1 female (minority sex). Large males were recorded significantly more often in copulation than small males when the female was large but not when the female was small. This was also the case when the group size was 24 males : 12 females or population density decreased by increasing the area of the experimental arena. In groups of 2females : 1 male, large females were recorded in copulation significantly more often than small females when the male was large but not when the male was small. Proportion of individuals of the minority sex that copulated was similar for males and females, regardless of body size. The average duration of copulation was similar for small and large males, but shorter for small than large females. The difference in the duration of copulation of small and large females was greater when it was with small rather than large males. The prolonged guarding of large females by small males may be explained by a trade-off between increasing the probability of inseminating an uneasily accessible high quality partner and copulating with more females.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
3. Decreased mating propensity of macropterous morph in a flightless wing-polymorphic insect, Pyrrhocoris apterus (Heteroptera)
- Creator:
- Socha, Radomír
- Type:
- article, model:article, and TEXT
- Subject:
- Pyrrhocoris apterus, non-functional wing polymorphism, wing morphs, males, females, mating success, and receptivity
- Language:
- English
- Description:
- The effect of wing length (brachyptery and macroptery) on mating activity was investigated in adult males and females of a flightless wing-polymorphic insect, Pyrrhocoris apterus (L.). Mating activity of the brachypterous and macropterous adult bugs was assessed according to 14 different parameters. The competition tests revealed higher numbers of copulations and greater duration of mating activity in brachypterous than in macropterous males. Brachypterous males are between two to four times more successful in competition for females than their macropterous counterparts, depending on the wing morph and physiological status of the females. Decreased mating success of macropterous males is associated with the smaller size of their accessory glands. Lowered competitive ability for mates is a likely penalty associated with macroptery. Receptivity tests showed the highest tendency to mate in reproductive brachypterous females, lower in macropterous females and the least in diapausing brachypterous females. This is the first report of decreased mating propensity of macropterous morphs in insects with non-functional wing polymorphism. The association of lowered mating success with the higher dispersal activity of the macropterous morph in this bug and a trade-off between the ability to reproduce and to disperse in the flightless wing-polymorphic insects is discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4. Downregulation of miR-30c-5p expression in colorectal cancer tissue is sex-dependent
- Creator:
- Herichova, Iveta, Reis, Richard, Hasakova, Kristína, and Vician, Marián
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- oestrogen receptor β, males, females, metastases, and survival
- Language:
- English
- Description:
- We report that decreased expression of miR-30c in tumor compared to adjacent tissue is sex-dependent in colorectal cancer (CRC) patients. High expression of miR-30c was associated with better survival in the whole cohort. When the cohort was split into male and female subcohorts, decreased miR-30c expression in tumor compared to adjacent tissue was observed only in males. Expression of miR-30c was decreased in CRC tumor tissue in male patients with nodes involvement compared to those without metastases in nodes and this difference was not observe in females. Next dependency of miR-30c expression on oestrogen receptor β (ERβ) mRNA levels in tumor was tested. In males with low expression of ERβ, we observed a significant decrease in miR-30c levels in patients with nodes involvement compared to those without nodes involvement. This difference was not observed in males with high ERβ mRNA levels and in females. Accordingly, males with low expression of ERβ and high expression of miR-30c showed a better survival that those with low expression ERβ and low expression of miR-30c. It is possible to conclude that whole cohort survival dependence on miR-30c is mostly generated by a subcohort of males with low expression of ERβ mRNA in tumor tissue.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5. Effect of temperature and photoperiod on the life cycle in lineages of Myzus persicae nicotianae and Myzus persicae s. str. (Hemiptera: Aphididae)
- Creator:
- Poupoulidou, Despoina, Margaritopoulos, John T. , Kephalogianni, Thiresia E., Zarpas, Kostas D. , and Tsitsipis, John A.
- Type:
- article, model:article, and TEXT
- Subject:
- Myzus persicae, Myzus persicae nicotianae, males, mating females, and sexual morphs
- Language:
- English
- Description:
- Male production was examined in 70 Myzus persicae s.str and M. persicae nicotianae clonal lineages at 17°C and 10L : 14D. Sixty nine were characterised by a partial loss of sexuality (androcyclic producing few males, and intermediates producing some males and mating females), and one was found to be permanently parthenogenetic. High within and between lineage variation was detected. Most (81%) of the clonal lineages produced few males (0-5 males per parent) and only 6% had male production (10-16 males per parent) comparable to that (12-23 males per parent) of seven lineages with a sexual phase (holocyclic) which were examined under the same conditions. The length of prenatal exposure to 10L : 14D increased the production of males. Continuous rearing under 10L : 14D at 12°C adversely affected male production in another intermediate clonal lineage. Temperature was found to affect the production of sexuals and to modify the short day photoperiodic response. The production of males and mating females was higher at 12°C than at 17°C in most of the 20 aforementioned clonal lineages with a partial loss of sexuality. Six lineages were permanently parthenogenetic at 17°C, but two of them produced a few males and the other four a few males and mating females at 12°C. Seven lineages which produced a few males at 17°C, also produced some mating females at 12°C. Lastly, photoperiod similarly affected the production of sexuals in two of the aforementioned clonal lineages, one with a sexual phase and one intermediate, although the regimes for the peak of sexuals were different. In both lineages, however, males appeared in a 0.5-1 h shorter scotophase than mating females.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. Serum copper, zinc and copper/zinc ratio in males: influence of aging
- Creator:
- Maďarič, A., Ginter, E., and Kadrabová, J.
- Type:
- article, model:article, and TEXT
- Subject:
- males, serum copper, serum zinc, copper/zinc ratio, and aging
- Language:
- English
- Description:
- Apparently healthy free-living (non-hospitalized) men aged 8-89 years (n=408) were studied to determine the effect of age on serum copper and zinc concentrations and the copper/zinc ratio. Mean values ± S.D. for age, serum copper and zinc levels and the copper/zinc ratio were as follow: 41.9 ±22.9 years, 1.15 ± 0.17 ¿rg/ml, 0.93±0.14 /¿g/ml and 1.25±0.19, respectively. In the elderly subjects above 75 years, a marked increase in serum copper concentrations and the copper/zinc ratio as well as a decrease in serum zinc concentrations were observed. Serum copper concentrations and the copper/zinc ratio correlated positively with age (pcO.OOOl).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Sexual dimorphism of five Cobitis species (Cypriniformes, Actinopterygii) in the Adriatic watershed
- Creator:
- Buj, Ivana , Šanda, Radek, Marčić, Zoran, Ćaleta, Marko, and Mrakovčić, Milorad
- Type:
- article, model:article, and TEXT
- Subject:
- loaches, morhological differences, females, males, and reproduction
- Language:
- English
- Description:
- Morphological differences between female and male spined loaches belonging to five species from the Adriatic basin were examined. Besides the presence of the Canestrini scale and the length of the pectoral fins, sexual dimorphism is also visible in the position of the pectoral fins, as well as in the length of the pelvic fins. Both pectoral and pelvic fins are significantly longer in males than in females, whereas pectoral fins of females are located more anteriorly then in males. Differences in the length of pectoral and pelvic fins among species are also revealed. The role of the secondary sexual characters in males is probably connected with their special mating behaviour. Furthermore, a hypothesis that habitat conditions have greater impact on body dimensions of females than males is proposed.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public