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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. Crustacean red pigment-concentrating hormone Panbo-RPCH affects lipid mobilization and walking activity in a flightless bug Pyrrhocoris apterus (Heteroptera) similarly to its own AKH-peptides
- Creator:
- Socha, Radomír, Kodrík, Dalibor, and Zemek, Rostislav
- Type:
- article, model:article, and TEXT
- Subject:
- Adipokinetic hormone, Panbo-RPCH, Peram-CAH-II, locomotion, lipid mobilization, females, flightless, macropterous, and Pyrrhocoris apterus
- Language:
- English
- Description:
- In the present study we tested whether the walking activity of macropterous females of the flightless wing-polymorphic bug Pyrrhocoris apterus (L.) can be stimulated by its native adipokinetic hormone Peram-CAH-II and the crustacean red pigment-concentrating hormone (Panbo-RPCH), and the effectiveness of the latter hormone in a lipid mobilization assay. Two different doses (10 or 40 pmol) of Peram-CAH-II or Panbo-RCPH were injected into 10-day-old macropterous females of P. apterus to evaluate their effects on the walking activity of treated females. The results obtained showed a significant stimulation of walking activity only with the lower dose (10 pmol) of either hormone Peram-CAH-II or Panbo-RPCH. On the contrary, the walking activity of the same-aged females of macropterous morph treated with the higher dose (40 pmol) of these hormones was decreased. The energy substrates mobilized in Panbo-RPCH-treated macropterous females were lipids. The question of whether the stimulation of locomotion by Panbo-RPCH is limited only to P. apterus or if it might also represent an important function of this hormone in other insects or even in crustaceans is discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4. 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
5. Do long- and short-winged adult females of the bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae) differ in lifespan and reproductive capacity?
- Creator:
- Socha, Radomír
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Heteroptera, Pyrrhocoridae, Pyrrhocoris apterus, firebug, females, wing morphs, lifespan, reproductive capacity, 2, and 59
- Language:
- English
- Description:
- 1_n the present study we tested whether long-winged (macropterous) and short-winged (brachypterous) adult females of the firebug Pyrrhocoris apterus (L.) differ in their reproductive capacity and length of life. The following seven physiological markers were measured in these females: lengths of the pre-oviposition period (pre-OP), inter-ovipositon period (inter-OP) and post-oviposition period (post-OP), and the mean number of eggs per batch, total number of eggs, mean total number of egg batches laid and lifespan of the females. The results showed that macropterous and brachypterous females significantly differed in the length of the pre-OP, which was significantly shorter in brachypterous (7.95 ± 1.75 days) than in macropterous females (26.84 ± 9.86 days), but there was no significant difference between the lengths of the inter-OP in brachypterous (4.00–8.79 days) and macropterous (3.00–9.89 days) females. In contrast the length of the post-OP was significantly longer in brachypterous (48.23 ± 30.95 days) than in macropterous females (35.02 ± 17.32 days). Except for the 2nd and 3rd egg batches there was no significant difference between the average numbers of eggs in the other egg batches laid by females of the two wing morphs., 2_Total number of eggs laid by macropterous females during their whole lifespan was not significantly lower (326.47 ± 155.65 eggs) than by brachypterous females (382.82 ± 207.52 eggs), but associated with the lower number of egg batches laid by macropterous (13) than by brachypterous females (19). However, there was no significant difference in the longevity of brachypterous (95.43 ± 41.21 days) and macropterous (93.40 ± 21.18 days) females. The relationship of these results to the reproductive arrest, inactivity of the endocrine gland, corpus allatum, and different levels of adipokinetic hormone in macropterous females is discussed., Radomír Socha., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. 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
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