A review of sexual initiating behavior by male and female cynomolgus monkeys and some species comparisons

The sexual initiating behavior of male and female cynomolgus monkeys (Macaca fascicularis) observed during standard laboratory tests is reviewed and compared with that of rhesus monkeys (M. mulatta) observed under identical conditions. Species differences in sexual behavior are related here to differences in habitat, sexual dimorphism, and the dominance gradient between the sexes. Compared with rhesus monkeys, cynomolgus monkeys appear to be more arboreal, less sexually dimorphic, and have a smaller dominance gradient between the sexes. They exhibit a facultative single-mount copulatory pattern rather than the serial mount pattern of the rhesus monkey. Female cynomolgus monkeys are less dominated than rhesus females by their male partners. Direct aggression between mates is more frequent and redirected aggression occurs less often than in rhesus monkeys. These behavioral differences affect the interpretation of changes in initiation rates that occur (1) during the menstrual cycle, (2) when females are ovariectomized and given hormone replacement treatments, and (3) when males are castrated and treated with androgens. We conclude that estradiol in the female and testosterone in the male increase the sexual motivation of both the treated and the untreated partner. Valid interpretations of changes in initiation rates depend on accurate and exclusive definitions of behavior and on a consideration of the behavioral context in which they are made.     

Sexual dimorphism in the size of nuclei with dioecious plants

Measurements of the size of the nuclei of dioecious plants showed that the nuclei of male and female plants differ in agreement with the larger quantity of chromatin. The male. plants ofRumex acetosella andMelandrium album had larger nuclei, their Y chromosome being larger than the X chromosome, the same is true forRumex acetosa where the Y chromosome is smaller but there are two in the set.Ginkgo biloba had larger female nuclei because the Y chromosome was smaller than the X. The curves obtained by grouping all the nuclei of both sexes never had two peaks with regard to the small differences between the classes of maximum frequency.     

Cytogenetic analysis of recombination in males of Drosophila ananassae

Cytogenetic studies of recombination in males of Drosophila ananassae were carried out by examining F₁ males derived from the mating of marker females, b se; bri ru of the BS stock, with males of two wild strains, TNG and L8. The male recombination values in both sections b-se (chromosome 2) and bri-ru (chromosome 3) are high in TNG F₁ but extremely low in L8 F₁ We demonstrate the presence of chiasmata in TNG F₁ males at a frequency capable of accounting for the observed recombination values. A unique series of “iso-site aberrations” was also observed in TNG F₁ males. Because of a parallelism in the distribution pattern between the chiasmata and the isosite aberrations, we propose that recombination in males of D. ananassae is meiotic in origin and that the iso-site aberrations are related to chiasma formation.     

Variability of skull and dental characteristics in Mus spicilegus from the northern border of its distributional range

Results of morphometric analysis of the mound-building mouse (Mus spicilegus) evaluated in this study originate from field trapping in the eastern part of Slovakia during the years 2003–2008. Twenty-four cranial and dental variables and the zygomatic index (A/B) of 80 skulls (43 males, 37 females) were measured and evaluated with respect to the sex of the mice. Despite the fact that the overlap of skull measurements in adult males and females was high, sexual dimorphism was confirmed for several skull and dental traits. On average, the values for adult females of M. spicilegus were higher than males, with the exception of dental traits and the zygomatic index. Significant differences between adult males and females were found for the mean values of ten skull and dental parameters (LB, LCb, FL, LD, LMd, LaZ, LM¹, LM₁, LaM¹ and LaM₁). The values for the zygomatic index (A/B) overlapped between both sexes, but the higher average values in adult males were statistically significant. The results showed that the variability of the species confirmed in this paper was probably caused only at the regional level and did not differ from the findings reported by several authors for species from neighboring countries.     

Exchange and Complementation of Genes Coding for Photosynthetic Reaction Center Core Subunits among Purple Bacteria

A mutant of the phototrophic species belonging to the β-proteobacteria, Rubrivivax gelatinosus, lacking the photosynthetic growth ability was constructed by the removal of genes coding for the L, M, and cytochrome subunits of the photosynthetic reaction center complex. The L, M, and cytochrome genes derived from five other species of proteobacteria, Acidiphilium rubrum, Allochromatium vinosum, Blastochloris viridis, Pheospirillum molischianum, and Roseateles depolymerans, and the L and M subunits from two other species, Rhodobacter sphaeroides and Rhodopseudomonas palustris, respectively, have been introduced into this mutant. Introduction of the genes from three of these seven species, Rte. depolymerans, Ach. vinosum, and Psp. molischianum, restored the photosynthetic growth ability of the mutant of Rvi. gelatinosus, although the growth rates were 1.5, 9.4, and 10.7 times slower, respectively, than that of the parent strain. Flash-induced kinetic measurements for the intact cells of these three mutants showed that the photo-oxidized cytochrome c bound to the introduced reaction center complex could be rereduced by electron donor proteins of Rvi. gelatinosus with a t_1/2 of less than 10 ms. The reaction center core subunits of photosynthetic proteobacteria appear to be exchangeable if the sequence identities of the LM core subunits between donor and acceptor species are high enough, i.e., 70 % or more.     

Effects of colony size and polyp position on polyp fecundity in the scleractinian coral genus Acropora

This study examined the effects of colony size and polyp position on six variables of polyp fecundity [egg number, egg size, total egg volume, total testis volume, total gonad volume, and gonad ratio (egg volume/testis volume)] in three tabular Acropora corals (Scleractinia), A. hyacinthus, A. japonica, and A. solitaryensis. Samples were collected from various colony sizes (n = 21–30 colonies species^?1), just before the predicted spawning at Kochi, Japan, in 2009. Five replicate polyps were sampled at three positions (center, middle, and outer) from the center to the marginal area in each tabular colony. Results indicated effects of colony size and polyp position on both male and female gonads polyp^?1. A positive effect of colony size was observed on variables of female gonads polyp^?1 (egg number, total egg volume) in A. hyacinthus only, while the positive effect on the variable of male gonads polyp^?1 (total testis volume) was common in all Acropora species, with total testis volume polyp^?1 increasing 2–4-fold from the small (200–400 cm²) to the large size class (5,000–9,000 cm²). Among the polyp positions, lower values were observed mostly in center polyps in A. hyacinthus, while lower values were observed only in outer polyps in the other Acropora species. The distinct patterns between A. hyacinthus and the other two Acropora species suggest different reproductive strategies at the species level. Further studies are needed to confirm the prevalence of these effects in scleractinian corals, which will broaden our understanding of reproductive life history strategies and improve the estimation of reproductive performance.     

Seed-Specific Expression of AINTEGUMENTA in Medicago truncatula Led to the Production of Larger Seeds and Improved Seed Germination

The increase of seed size is of great interest in Medicago spp., to improve germination, seedling vigour and, consequently, early forage yield as well as for optimizing seeding techniques and post-seeding management. This study evaluated the effects of the ectopic expression of the AINTEGUMENTA (ANT) cDNA from Arabidopsis thaliana, under the control of the seed-specific USP promoter from Vicia faba, on seed size, germination and seedling growth in barrel medic (Medicago truncatula Gaertn.). All the transgenic T₂ barrel medic lines expressing ANT produced seeds significantly larger than those of control plants. Microscopic analysis on transgenic T₃ mature seeds revealed that cotyledon storage parenchyma cells were significantly larger and contained larger storage vacuoles than those of the untransformed control. Moreover, the percentage of germination was significantly higher and germination was more rapid in transgenic than in control seeds. Our results indicate that the seed-specific expression of ANT in barrel medic led to larger seeds and improved seed germination, and revealed a regulatory role for ANT in controlling seed size development.     

The expression of aggression in old world monkeys

The expression of agonistic behavior in adult and juvenile members of both sexes was studied in groups of from 23 to 93 animals representing Macaca mulatta, M. arctoides, M. nemestrina, M. nigra, and Cercocebus atys. Data were collected using focal animal techniques over a period of 1 year for each group. Adult male biting was notably infrequent in all cases, and adult male participation in agonistic encounters was less frequent than for any other age-sex class, especially in the groups with the highest agonistic rates. Adult male agonistic behavior was often expressed as aggression but seldom involved contact forms of aggression, and biting constituted the smallest proportion of contact aggression for all age-sex classes. Adult males were also seldom the targets of aggression and had the highest rates for shaking of objects and bouncing displays. A tendency for the most severe forms of aggressive expression to be most frequent in those animals least capable of inflicting injury was noted in all groups, along with a tendency for aggression to be directed toward immature animals. Sex differences in aggressive expression and responses to aggression were noted, but the frequency of receipt of aggression was not directly reflected in the wounding noted. Different means to achieve the same consequence, infrequent adult male damaging attacks, are suggested to operate in the several groups studied.     

Age structure, growth and mortality estimates of an endemic Ptychobarbus dipogon (Regan, 1905) (Cyprinidae: Schizothoracinae) in the Lhasa River, Tibet

Ptychobarbus dipogon is an endemic fish in the Yarlung Tsangpo River, but its biology is poorly known. We sampled 582 specimens (total length, TL, between 70.6 and 593.0 mm) from April 2004 to August 2006 in the Lhasa River, Tibet. We estimated ages based on the counts of alternating opaque and translucent zones (annuli) in thin transverse sections of lapilli otoliths. Ages ranged from 1⁺ to 23⁺ years for males and 1⁺ to 44⁺ for females. The observed 44⁺ years was the oldest reported for schizothoracine fishes. Females attained a larger size than males. The TL–weight relationship was W?=?7.12?×?10^?6 TL ^3.006 for combined sexes. The growth parameters fitted von Bertalanffy growth functions were $L_\infty = 598.66\,{\text{mm}}$ , k?=?0.0898 year^?1, t ₀?=??0.7261 year and $W_\infty = 1585.38\;{\text{g}}$ for females and $L_\infty = 494.23{\text{ mm}}$ , k?=?0.1197 year^?1, t ₀?=??0.7296 year and $W_\infty = 904.88{\text{ g}}$ for males. The longevities of 32.7 year for females and 24.3 year for males were similar to the observed ages. Using an empirical model we estimated the instantaneous rate of total mortality (Z) at 0.28 per year in the lower reaches. Z in the upper and middle stocks was close to the M because of unexploited or lightly exploited stock. Protracted longevity, slow growth, low natural mortality and large body size were typical characteristics of P. dipogon. The current declining trend of P. dipogon could be prevented by altering fishing regulations.     

The effect of female call on male howling in red howler monkeys(Alouatta seniculus)

Howler (Alouatta spp.)females often produce loud calls together with the males. Sometimes these howls are not heard above the much louder male call, but on other occasions most of the howls are produced by the females. Observations indicate that female howls are aggressive. Females howl at other troop females and at extratroop females; they also sit close to their mates and howl at other males. I suggest that howling by the females with their mate is important in strengthening the pair bond whereby the male recognizes his infants and acts protectively toward them. Playback experiments of female howls elicited more response from the males than did recordings of male/female and male-only howls, supporting the hypothesis that females howl in order to incite competition among the males.     

Managing hunted populations through sex-specific season lengths: a case of the Common Eider in the Baltic-Wadden Sea flyway population

Management of harvested wildlife populations aims to protect species from overexploitation and ultimately extinction, by regulating exploitation towards achievable sustainable levels. However, assessments of impact and sustainability of implemented management actions on a population level are scarce. This study assesses effects of changes in hunting season length imposed on the Baltic-Wadden Sea Common Eider Somateria mollissima population, including differential restriction on hunting of the sexes. The potential impact of these changes on the population was assessed by simple demographic matrix projections. Since the early 1990s, this population has declined at ca. 6.3 % per annum, and the male/female ratio among shot birds has fallen from 3:2 to about 3:1. Concerns in Denmark regarding the conservation status and sustainability of contemporary levels of exploitation resulted in shortening the open season by 44 and 46 days for females and 13 and 15 days for males from the hunting seasons 2004/2005 and 2011/2012 onwards, respectively. These reduced the kill of adult females by 82 %, adult males by 31 %, juvenile females by 58 % and juvenile males by 55 %. The observed reduction in the kill of adult females following both changes in 2004/2005 and 2011/2012 matched the expected changes based on the seasonal distribution of sexes in the bag prior to the change. Post 2004/2005 hunters killed more adult males, but shot markedly fewer juvenile birds than expected. Demographic modelling of the female population showed that the effects of the reduced hunting would correspond to an increase in the annual population growth rate from the previous ?6.3 to ?3.6 % (post 2004) and ?1.6 % (post 2011). The model also predicted that a full ban on hunting female eiders (adults and juveniles) would lead to a positive population growth rate of 0.7 %. Taking into account the conservative model estimates and natural variations in annual breeding success, the implemented changes in sex-specific regulation of hunting may potentially be an effective management tool to halt the decline of the Baltic-Wadden Sea eider population, potentially rendering such levels of hunting sustainable under prevailing conditions.     

Evidence of latitudinal migration in tri-colored bats, Perimyotis subflavus

Background

Annual movements of tri-colored bats (Perimyotis subflavus) are poorly understood. While this species has been considered a regional migrant, some evidence suggests that it may undertake annual latitudinal migrations, similar to other long distance North American migratory bat species.

Methodology/Principal Findings

We investigated migration in P. subflavus by conducting stable hydrogen isotope analyses of 184 museum specimen fur samples and comparing these results (δD_fur) to published interpolated δD values of collection site growing season precipitation (δD_precip). Results suggest that the male molt period occurred between June 23 and October 16 and 33% of males collected during the presumed non-molt period were south of their location of fur growth. For the same time period, 16% of females were south of their location of fur growth and in general, had not travelled as far as migratory males. There were strong correlations between δD_fur from the presumed molt period and both growing season δD_precip (males – r ² = 0.86; p<0.01; females – r ² = 0.75; p<0.01), and latitude of collection (males – r ² = 0.85; p<0.01; females – r ² = 0.73; p<0.01). Most migrants were collected at the northern (>40°N; males and females) and southern (<35°N; males only) extents of the species'' range.

Conclusions/Significance

These results indicate a different pattern of migration for this species than previously documented, suggesting that some P. subflavus engage in annual latitudinal migrations and that migratory tendency varies with latitude and between sexes. We suggest that this species'' hibernation ecology makes it particularly susceptible to long winters, making migration from the northern extent of the species'' range to more southern hibernacula preferable for some individuals. Fur δD values for some of the northern individuals may indicate an increase in the currently accepted northern range of this species. Sex-biased differences in migration may be the result of differences in reproductive pressures.     

Susceptibility to db gene and streptozotocin-induced diabetes in C57BL mice: control by gender-associated,MHC-unlinked traits

H-2 haplotype differences distinguish the related C57BL/KsJ (BKs) and C57BL/6J (B6) inbred strains. BKs mice are more susceptible to diabetes induction by a recessive obesity gene, diabetes (db), or by multi-dose streptozotocin (MSZ) administration. The purpose of this study was to evaluate whether the H-2 differences were the important genetic background modifiers determining inbred strain susceptibility or resistance to these diabetogenic stresses. Diabetes susceptibility of BKs.B6-H-2 ^b congenic mice was compared with that of the parental BKs and B6 stocks. In addition, diabetes severity was studied in (B6 × BKs)F₁ and F₂ db/db mice and an H-2 segregation analysis was performed. BKs susceptibility genes expressed in a dominant fashion in the F₁ generation, and were transmitted to F₂ db/db males without apparent segregation. No association between H-2 ^b haplotype and B6-type diabetes resistance was found in response to either the db mutation or to MSZ. Insulitis, associated with development of hyperglycemia in BKs males, also occurred in the H-2 ^b congenic stock. However, an apparent interaction between H-2 ^b haplotype, the db mutation (on chromosome 4), and male gender (Y chromosome?) was indicated by a segregation ratio distortion in recovery of this genotype. A more moderate diabetes in some F₂ db/db females suggested that non-MHC-linked genes controlling sex steroid metabolism were the important determinants of diabetogenic sensitivities in the C57BL stocks. In support of the latter, strain differences were demonstrated in activity levels of steroid sulfatase, which is regulated by a sex-linked gene likely expressed on both the X and Y chromosome, and which may control tissue levels of active androgens and estrogens. We show that the diabetes-susceptible F₁ hybrids exhibit the higher activity associated with the BKs strain.     

Relative growth and reproductive cycle of the date mussel Lithophaga lithophaga (Linnaeus, 1758) sampled from the Bizerte Bay (Northern Tunisia)

Relative growth and the reproductive cycle of the date mussel Lithophaga lithophaga were studied from September 2002 to October 2003 in the Bizerte Bay (Northern Tunisia). Relationships between shell length and shell width, shell height as well as volume-related variables (shell dry weight, soft tissues dry weight and total wet weight) showed negative allometries in both sexes except for shell width in males (isometry) and shell height in both sexes (positive allometry). The sex ratio was unbalanced, within the length range of 6–48 mm, 49.43 % of the animals were males, 24.39 % females and 26.17 % sexually undifferentiated; within the length range of 49–92 mm, the respective values were 41.19, 52.7 and 6.1 %. Histological investigations as well as analyses of the condition index and the gonadosomatic index (CI and GSI) revealed the presence of a single reproductive cycle per year. Spawning occurred at the end of August and early September and was associated with a decrease in seawater temperature and salinity. A resting phase occurred in winter, coinciding with the lowest water temperatures. Histological examinations of the gonads of a total of 130 specimens revealed only two cases of hermaphroditism. The present study constitutes a useful baseline for a sustainable management of local wild stocks of L. lithophaga.     

Comparison of age and growth performance of diploid and tetraploid loach <Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis> in the Yangtze River basin,China

Diploids and tetraploids of the cyprinid loach Misgurnus anguillicaudatus coexist in many natural habitats in Asia. However, little is known about the biological and ecological differences between these two ploidy forms. We examined age, body size and growth rates of fish in a mixed ploidy population of M. anguillicaudatus in the Yangtze River basin in China. The sex ratios of both diploid and tetraploid M. anguillicaudatus were highly skewed toward females, who tended to be larger than males. The age distributions of the collected specimens clearly indicated that tetraploids lived longer than diploids. For example, we found a substantial number of tetraploids that were 5+ years old, while the oldest diploids were 4+ years old. Tetraploids were also longer and heavier than diploids for both sexes. Using the empirical body size and age data, we inferred the growth patterns of these fish with the von Bertalanffy growth function. The estimated asymptotic body lengths (L _∞) indicated that tetraploids could indeed achieve larger body sizes than diploids. This difference was partially due to the increased growth rate, as demonstrated by lower growth coefficient (K) and higher growth performance index (φ’). In sum, we show that tetraploid M. anguillicaudatus exhibited significantly increased longevity and superior growth performance compared to diploids. These differences may contribute to the ecological competitiveness of tetraploid M. anguillicaudatus, thus enabling them to coexist with diploids in certain ecological settings.     

Age and growth assessment of western North Atlantic spiny butterfly ray <Emphasis Type="Italic">Gymnura altavela</Emphasis> (L. 1758) using computed tomography of vertebral centra

Life history strategies of batoid fishes have evolved within dynamic marine ecosystems. Adaptations in reproductive and developmental biology are paramount to the survival of species, and therefore knowledge of growth rates to maturity is fundamental for identifying constraints on the conservation of populations. The butterfly rays (Myliobatiformes: Gymnuridae) are highly derived batoids with generally low reproductive potentials for which age and growth information remains unknown. In this study we applied high-resolution X-ray computed tomography (HRXCT) to vertebral centra from a stingray for the first time to estimate age, and used a multimodel approach to investigate growth of spiny butterfly ray, Gymnura altavela. Estimated ages of the oldest male and female were 11 and 18 yrs. at disk widths (WD) 1355 mm and 2150 mm, respectively. Disk width-at-age data were analyzed using three growth models (von Bertalanffy, logistic, Gompertz), and the most parsimonious and empirically supported model was the logistic function with sex treated as a fixed effect on asymptotic disk width (WD _∞ ) and k parameters. Model parameter estimates were (males) WD _∞  = 1285.46 ± 67.27 mm, k = 0.60 ± 0.10, and (females) WD _∞  = 2173.51 ± 129.78 mm, k = 0.27 ± 0.04. Results indicated sexually dimorphic growth patterns, with males growing faster and reaching asymptotic size at earlier ages than females. These age and growth results are the first reported for the genus, and suggest that G. altavela grows at a similar rate as some teleosts and batoids, and relatively fast among chondrichthyans.     

Population biology of the red gurnard (Aspitrigla cuculus L.; Triglidae) in the inshore waters of Eastern Anglesey and Northwest Wales

ICES has identified red gurnard Aspitrigla cuculus (L.) as a potential commercial species and recommended that monitoring programmes should be conducted to derive information on biological parameters for stock assessment purposes. In this paper, data on the population biology of red gurnard in the coastal waters of Northwest Wales and Eastern Anglesey are presented. Total length (TL) of fish sampled ranged from 15.4 to 35.0 cm (males) and 10.5 to 43.1 cm (females), with the majority of females between 20 and 30 cm TL (70.0%) and males between 20 and 30 cm TL (71.0%). TL/weight (W) relations were similar between immature and mature individuals for both sexes and between both sexes (all maturity stages combined), producing a combined data equation W = 0.005 TL^3.19. Age of fish ranged from 1 to 7 years and 1 to 6 years, respectively, for females and males, with the majority of females age 3 (37%) and the majority of males age 2 (49%). The age structures of female and male red gurnards were significantly different, with the older age classes consisting predominantly of female fish. Both males and females exhibited similar asymptotic growth patterns; the combined von Bertalanffy growth function was . Instantaneous rates of total mortality were calculated as 1.13 year^?1 for males and 0.98 year^?1 for females. The size (L₅₀) and age at first maturity (A₅₀) were estimated to be 26.3 cm TL and 3.6 years for males, 28.1 cm TL and 3.5 years for females and 25.6 cm TL and 3.7 years for both sexes combined.     

Cyclic AMP and genetic sterility of a male restricted (H re /+) mutant of Rattus

Restricted (H ^re /+) male rats marked by a coat color pattern have normal testes at birth. By 9 days postpartum, testes of the mutant animals are smaller than normal and by approximately 90 days of age the animals are sterile. The genetically sterile testes are totally devoid of spermatogonial cells, spermatocytes, spermatids, and spermatozoa, with only Sertoli cells remaining in the seminiferous tubules. Cyclic AMP concentrations in the whole testes (and the seminiferous tubules) of the mutant males are approximately 10–35% greater than in testes of control males when tested at intervals from 5 to 120 days of age. The possible role of excess cyclic AMP in reducing the rate of mitotic division of spermatogonial cells while enhancing differentiation of spermatogonial cells into spermatozoa is discussed. Such a change in the respective rates of mitotic and meiotic divisions would ultimately deplete the mutant testes of all spermatogonial cells.