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1

Flower colour polymorphism in Geranium nepalense (Geraniaceae): adaptation to non-pollinator agents

100%
Tang X. X., Liu H. L., Zhang C., Wang Y., Zhang X. M., Yi Y.
Polish Journal of Ecology
|
2016
|
tom 64
|
nr 4
Flower colour polymorphism is attributed to pollinator or non-pollinator mediated selection. Geranium nepalense has common white morph and very rare pink morph. We compared pollinator visitation frequencies, temperature and soil moisture between two morphs in the mixed morph population. We also compared morph ratio and reproductive success between white and pink flower individuals. Our results indicated that no visitor groups were different between two colour morphs. But visitor groups differed in visits between two years. Halictidae preferred pink morph in the year of 2012 but showed no discrimination in 2014, whereas Syrphidae preferred white morph in 2014 but no discrimination in 2012. Overall, pink morph produced more seeds than white morph, but exhibited variation between two years. However, visitor discrimination was not the main cause of the difference in female fitness. Soil moisture was not different between two colour morphs. Temperature of white morph was lower than pink in evening but not different in morning and noon. The results indicated that non-pollinator factors may exert the selective pressure to maintain the flower colour polymorphism in this species. Although pollinators did not exert selection on the flower colour polymorphism, we suggest that they provided potential pollination environment of fluctuating selection to drive flower colour evolution if visitors were limited.
2

Gender dimorphism in the exercise-naive murine skeletal muscle proteome

84%
Metskas L. A., Kulp M., Scordilis S. P.
Cellular and Molecular Biology Letters
|
2010
|
tom 15
|
nr 3
507-516
Skeletal muscle is a plastic tissue with known gender dimorphism, especially at the metabolic level. A proteomic comparison of male and female murine biceps brachii was undertaken, resolving an average of 600 protein spots of MW 15–150 kDa and pI 5–8. Twenty-six unique full-length proteins spanning 11 KOG groups demonstrated statistically significant (p<0.05) abundance differences between genders; the majority of these proteins have metabolic functions. Identified glycolytic enzymes demonstrated decreased abundance in females, while abundance differences in identified oxidative phosphorylation enzymes were specific to the proteins rather than to the functional group as a whole. Certain cytoskeletal and stress proteins showed specific expression differences, and all three phosphorylation states of creatine kinase showed significant decreased abundance in females. Expression differences were significant but many were subtle (≤ 2-fold), and known hormonally-regulated proteins were not identified. We conclude that while gender dimorphism is present in non-exercised murine skeletal muscle, the proteome comparison of male and female biceps brachii in exercise-naive mice indicates subtle differences rather than a large or obviously hormonal dimorphism.
3

Flower structures and flowering biology in Tinantia anomala (Torr.) CB Clark

84%
Winiarczyk K., Gebura J., Stolarz M.
Acta Biologica Cracoviensia. Series Botanica. Supplement
|
2014
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tom 56
|
nr 1
4

Evolution of phenotypic sex differences in cooperative species: is competition an opposing force?

84%
Dias R. I.
Acta Ornithologica
|
2018
|
tom 53
|
nr 2
Sexual selection is generally thought to be weak in cooperative breeding species, largely because polygamous mating patterns that drive sexual selection can erode the kin-selected benefits of cooperation. Social selection, on the other hand, is expected to be strong among cooperative species especially because of the intense competition over status and resource access. In support of this view, several studies have shown monogamous mating and little sex difference in cooperative species. However, most previous studies have focused on species with relatively simple social systems and few studies have examined how mating patterns, social organization and ecological attributes have influenced the evolution of ornamentation in cooperative species. Here I used secondary data to examine several hypotheses and shed some light on how social and sexual selection influenced the evolution of phenotypic sex traits in cooperatively breeding birds. Despite the broad assumption that cooperative breeding species are monomorphic, results demonstrate that sex differences and the presence of ornamentation are widely spread in the group. Stable environments with higher precipitation are associated to the strongest differences between sexes. Results indicate that although extrapair matings and environment attributes are determinant to the evolution of sex differences, males and females of cooperative species seem to be more alike than their non-cooperative counterparts. The extent of mutual ornamentation found in cooperative species indicates that the combination of both sexual and social selection are imperative to determine how evolution has shaped phenotypic attributes in cooperative species.
5

The ecological importance of seed dimorphism in corn spurry (Spergula arvensis L.). I. The effects of day length on seed germinability

84%
Kucewicz M., Gojlo E.
Polish Journal of Ecology
|
2013
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tom 61
|
nr 4
Spergula arvensis L. (corn spurry) is a heteromorphic species of the Caryophyllaceae family, that produces two types of seeds with a smooth (non papillate, NP) or papillate (P) coat. The plant flowers and produces fruit between May and September, a period marked by a gradual decrease in day length. The objective of this study was to determine the effects of day length on the germinability of heteromorphic seeds. In addition, we examined the frequencies of non papillate and papillate seeds in four populations. Germination tests were performed on seeds harvested from plants grown in a greenhouse under conditions simulating long days (17 hour photoperiod) and short days (12 hour photoperiod). Heteromorphic seeds incubated in water at various temperatures (10–30°C) over a period of 4 weeks remained dormant. Corn spurry seeds had different responses to the addition of nitrate after four weeks of pre-treatment. Both seed morphs kept at a temperature of 10–20°C did not germinate or their germination rates did not exceed 6%. Seeds incubated at 25°C and 30°C broke dormancy. NP seeds from plants growing under long- and short-day photoperiods were characterized by higher germinability than P seeds at both temperatures. The above-mentioned results indicate that variations in light exposure during plant growth and development do not contribute to somatic heteromorphism of S. arvensis seeds. Day length has no significant effect on the germination of heteromorphic seeds. The populations were heteromorphic with respect to plants having papillate seeds and plants having non papillate seeds. The majority of individuals were monomorphic and produced capsules containing only one type of seed. Heteromorphic individuals produced capsules containing: a) NP seeds, and b) P seeds, and c) mixed seeds. The analyzed populations were characterized by a predominance of P seeds in the overall seed pool.
6
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The number of motor units in the medial gastrocnemius muscle of male and female rats

84%
Celichowski J., Drzymala-Celichowska H.
Journal of Physiology and Pharmacology
|
2007
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tom 58
|
nr 4
The number of motor units in the hindlimb locomotor muscle - the medial gastrocnemius - was estimated in male and female Wistar rats by comparison of the whole muscle tetanic force to the mean tetanic force of its motor units. Functional isolation of motor units was achieved by electrical stimulation of single axons from ventral roots of L4 - L5 spinal nerves, while the whole muscle force was measured during stimulation of the sciatic nerve. The medial gastrocnemius muscle is approximately 1.5 times bigger by mass, and is innervated by 10% more motoneurones in males compared to females. Estimation of the force that can be generated by the three types of motor unit in the studied muscle revealed that in both sexes fast fatigable units are responsible for over 60% of the total force output whereas the percentage of the force output contributed by slow units in females is approximately twice that in males. Concluding, the motor innervation of hindlimb skeletal muscles is sexually dimorphic and in the rat male medial gastrocnemius muscle contains about 10% more motor units than in females.
7

Dimorphism and abnormality in the male reproductive system of four digenean species [Trematoda]

84%
Kanev I., McCarthy A., Radev V., Dimitrov V.
Acta Parasitologica
|
1994
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tom 39
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nr 2
8

Neuroendocrine response during stress with relation to gender differences

84%
Jezova D., Jurankova E., Mosnarova A., Kriska M., Skultetyova I.
Acta Neurobiologiae Experimentalis
|
1996
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tom 56
|
nr 3
9

Does size dimorphism reduce competition between sexes? The diet of male and female pine martens at local and wider geographical scales

84%
Zalewski A.
Acta Theriologica
|
2007
|
tom 52
|
nr 3
Sex-specific niche segregation is often used to explain sexual size dimorphism (SSD). However, whether food niche partitioning between sexes occurs as a case of sexual size dimorphism or by other mechanisms, such as behavioural dimorphism or habitat segregation, remains poorly understood. To evaluate the nature and extent of food-niche differentiation between sexes in a solitary predator I examined variation in the diet of male and female pine martensMartes martes Linnaeus, 1758 in years of high and low rodent abundance. Small mammals were the most important prey for pine martens in years of both low and high rodent abundance (occurring in more than 49% of scats). Birds, invertebrates and plant material were relatively common food items in summer diet, whereas ungulate carcasses were often consumed in autumn—winter. In general, males consumed more ungulate carcasses, plant material, amphibians and reptiles than did females, whereas females preyed more on squirrels and birds than males. There was significant seasonally dependent, between-sex variation in the occurrence of shrews, small rodents, other mammals, birds and invertebrates in marten diet. Whereas the occurrence of bank vole, birds, carcasses and plant material changed between sexes, seasons and years with various rodent abundances, both sexes consumed larger prey and had increased food niche breadth in years of low compared with high rodent abundance. Neither prey size nor food niche breadth were significantly different between males and females. The food-niche overlap between sexes was consistently lower in spring and in years of low rodent abundance. A wider geographical comparison of different marten populations showed that the diet of males and females varied significantly between locations. Females consistently preyed on squirrels and birds, whereas males fed more often on ungulate carcasses and plant material. Local and geographical comparison of male and female diets suggest that food-niche partitioning between male and female pine martens changes across different habitat and food conditions, and is not related to sexual size dimorphism, but rather to behavioural differences between sexes.
10
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Content available

Sexual dimorphism and pore systems in Ordovician ostracodes

67%
Schallreuter R. E. L., Hinz-Schallreuter I. C. U.
Acta Palaeontologica Polonica
|
2010
|
tom 55
|
nr 4
Open antra, a special form of external brood pouches in Ordovician ostracodes suitable for both egg and brood care, are enabled by the associated pore system. Special kinds of radial pores connected with the adventral sculptures are described for the first time. Relationships exist between antral development and lifestyle in that open antra occur in nektobenthic taxa, while closed antra (false brood pouches) are connected with a benthic lifestyle. Taxa, particularly those with open antra, which are morphologically very similar in being non−lobate or non−sulcate, can be distinguished by the construction of the respective antra and the associated pore systems, as exemplified by Levisulculus, Swantina, and Ampletochitina.
11
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Content available

Dimorphism in tetragonitid ammonoid Tetragonites minimus from the Upper Cretaceous in Hokkaido, Northern Japan

67%
Aiba D.
Acta Palaeontologica Polonica
|
2022
|
tom 67
|
nr 4
12

Ultrastructure and phylogeny of Pleistophora beebei sp. nov. (Microsporidia) infecting the Amazonian teleostean Brachyhypopomus beebei (fam. Hypopomidae)

67%
Casal G., Matos E., Rocha S., Sindeaux-Neto J., Al-Quraishy S., Azevedo C.
Acta Protozoologica
|
2016
|
tom 55
|
nr 4
13

Wide intersexual niche overlap of the specialized White-backed Woodpecker Dendrocopos leucotos under the rich primeval stands in the Bialowieza Forest, Poland

59%
Czeszczewik D.
Ornis Polonica
|
2010
|
tom 51
|
nr 4
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