Female cloacal protuberance of the polygynandrous Alpine Accentor Prunella collaris: histological features and possible functional significance

This paper describes the histological features of the prominent cloacal protuberance (CP) of sexually mature females of the polygynandrous Alpine Accentor Prunella collaris . In the copulation period, the CP of the prelaying mature female developed remarkably and the lips of the vent turned brilliant scarlet. Macroscopic and microscopic examination of the cloacal region from females of different ovarian maturity showed that the formation of the CP was mainly due to the hypertrophy of the cloacal musculature, i.e. the sphincter cloacae muscle and levator cloacae muscle, and to the development of the associated connective tissue in the sexually mature female. The scarlet coloration of the cloacal lips was ascribed exclusively to the development of the dermal vascular plexus accompanied by hyperaemia, as characterized by the dilated blood vessels filled with blood. There was no evidence that skin pigmentation was involved in the scarlet coloration of the cloacal lips. We speculate that the morphological changes in the cloacal lips of the female Alpine Accentor are mediated hormonally by the brain–pituitary–gonadal axis.     

Territory and group living in the polygynandrous Alpine Accentor Prunella collaris

The spacing system of Alpine Accentors Prunella collaris was studied on the summit of Mt. Norikura in central Japan for five breeding seasons. This species lived in groups (mean 7.2 individuals), sharing large areas of their individual home ranges within which all activities occurred. Membership of a group was closed and stable within a breeding season. The group home ranges overlapped little with each other, and antagonistic behaviour, including communal defence, was observed at the boundaries. Each female established an exclusive area around her own nest which she defended against other females (but not males) within the shared home range, but her activities (feeding, singing and mating) were observed over the whole of the group home range. Members of the same group moved around and fed together within the home range during the prebreeding season, but individual birds tended to become more solitary as the breeding season progressed. These results suggest that the primary breeding unit of Alpine Accentors is a group consisting of five to ten members who share a group territory which contains all the resources necessary for living and breeding, but this species is not a typical social one in which all members move around together within their group territory.     

Effects of supplemental feeding and female age on timing of breeding in the Alpine Accentor Prunella collaris

Supplemental food in the form of millet seed was provided to 1-year-old and older (2:2-year-old) female Alpine Accentors Prunella collaris, and the effect on timing of breeding was studied over four breeding seasons in central Japan. Only 1-year-old females responded to the supplemental food: additional food advanced their settlement date, the onset of the development of a cloacal protuberance and laying date. In contrast, no effect of the experimental feeding was found on the timing of breeding in older females and they invariably bred earlier than 1-year-old females. Having settled on the breeding grounds, females developed the cloacal protuberance and retained it for about 1 month until the last egg in the first clutch was laid. The development period of the protuberance corresponded to the copulation period. Because the copulation period was not shortened by extra food and no significant difference occurred in either of the two age classes, it is necessary for earlier breeding birds to accumulate the nutrients needed to form the protuberance as well as the eggs. Although older females relied less on supplemental food, they were significantly heavier and formed the cloacal protuberance earlier than 1-year-old females. One-year-old females depended more heavily on supplemental food than did older ones and the duration between settlement date and the onset of development of the protuberance of 1-year-olds was reduced by additional food. These results raised the possibility that older females fly from their wintering grounds carrying some food reserves which they can use for forming the protuberance, while 1-year-old females collect the food needed for forming it on the breeding grounds.     

Microscopic structure of the sperm storage tubules in the polygynandrous alpine accentor, Prunella collaris (Aves)

We describe the microscopic structure of the sperm storage tubules (SSTs) of the polygynandrous alpine accentor, Prunella collaris. The SSTs were found at the utero‐vaginal junction of the oviduct and were composed of a single layer of columnar epithelium. The cells of the tubule proper were non‐ciliated and had a round or oval nucleus in their basal portion. Their cytoplasm was finely or coarsely vacuolated due to lipid inclusions. Under the electron microscope, the epithelial cells exhibited a number of mitochondria, Golgi bodies, occasional lysosome‐like dense bodies, granular endoplasmic reticula, junctional complex, and tonofilaments. The apical margin of the cells was fringed with numerous microvilli. The epithelial lining of the SSTs was devoid of mucous cells, but showed occasional infiltration of lymphoid cells. No contractile elements were found in association with the SSTs, but a close apposition of unmyelinated nerve fibres to the basal part of the SST cells was recognized. Intraluminal sperm were arranged in bundles, and their heads were orientated towards the distal portion of the SSTs. Evidence for engulfment of sperm by the SST cells was obtained for the first time. A sign of atrophy or regression of the SSTs was found in one specimen.     

Characterization of nine polymorphic microsatellite loci from the alpine accentor Prunella collaris

Nine polymorphic microsatellite loci were isolated and characterized from the alpine accentor Prunella collaris. In analyses of 50 unrelated individuals, allelic diversity ranged from 2 to 7, and observed heterozygosity ranged from 0.08 to 0.70. Except for one locus (Pco2), variability was relatively low even in long repeat loci. This result may be due to the high return rate to the natal population. Primer sets were also tested in Japanese accentor Prunella rubida, and seven out of nine loci were successfully amplified.     

巢中的位置对鸲岩鹨亲鸟递食率的影响

2 0 0 2年 4～ 8月在中国科学院海北高寒草甸生态系统定位站研究了鸲岩鹨 (Prunellarubeculoides)亲鸟的递食率与巢中位置的关系。结果表明 :亲鸟的总递食率对巢中的每个具体位置有显著变化(Kruskas WallisH =1 4 63 3 ,P <0 0 1 ,df=3 ) ;雄性和雌性对巢中的位置有不同的响应 ,雄性对巢中的每个具体位置的递食率有显著差异 (H =1 6 72 0 ,P <0 0 1 ,df=3 ) ,而雌性递食率差异不显著 (H =3 5 5 7,P>0 0 5 ,df=3 ) ;雄鸟和雌鸟间递食的方式随着日龄和日时间变化也有显著差异。结果证实巢中的位置能够影响鸲岩鹨亲代资源的分配 ,同时也证实了鸲岩鹨双亲对巢中的位置有不同的响应。     

Sperm competition and the reproductive organs of the male and female Dunnock Prunella modularis

The morphology of the external and internal reproductive organs of male and female Dunnocks Prunella modularis are described in relation to the intense sperm competition characteristic of this species' mating system. Males have a relatively large cloacal protuberance, seminal glomera (sperm store) and testes. The seminal glomera contain about 1060 times 10⁶ spermatozoa, probably sufficient for numerous copulations. The female's uterovaginal junction comprised 16 primary mucosal folds, each containing an average of 87 sperm storage tubules (SSTs): 1398 in total. SSTs were 370 μm in length and SSTs filled with sperm had an internal diameter of 12.2 μm. The morphology, number, size and storage capacity of SSTs were similar to that for other passerines, despite the female Dunnock's high copulation rate. Sperm ejected during the Dunnock's precopulatory display is thought to originate from the vagina rather than from the SSTs.     

Estrogen target sites in the cloacal region of female and male chick embryos

Summary After intravenous injection of ³H-estradiol in the 12-day old chick embryo, radioactivity is concentrated in nuclei of certain cells in the cloacal area. The nuclear labeling is observed in mesenchymal cells along the different portions of the cloaca, and in an unidentified tissue located laterally to the cloaca. The labeled mesenchymal cells display a definite pattern of distribution along the epithelial wall of the cloaca, identical both in male and in female embryos. In the adjacent bursa of Fabricius, cells do not concentrate labeled hormone in their nuclei. The presence of estrogen receptors in the cloacal area of embryos of either sex adds evidence, at the cellular level, to support the concept of a neutral, or undifferentiated, sex with estradiol inhibiting this neutral male differentiation.Visiting scientistSupported by a Fellowship from the Délégation Générale à la Recherche scientifique et technique, Paris, France     

Aromatase inhibition blocks the expression of sexually-motivated cloacal gland movements in male quail

In Japanese quail (Coturnix japonica), activation of appetitive and consummatory aspects of male sexual behavior requires aromatization of testosterone (T) into estrogens. Appetitive male sexual behavior (ASB) is usually assessed with the use of a learned social proximity procedure. In the present experiment, we investigated the role of estrogens in the activation of an another index of ASB, the female-induced activation of rhythmic cloacal sphincter movements (RCSMs) that are produced in reaction to the visual presentation of a female. Consummatory sexual behavior (CSB) was also assessed by the frequency and latency of copulatory behaviors. Castrated male quail were treated with Silastic implants filled with T in association with chronic injections of the aromatase inhibitor Vorozole (R83842; 1mg/kg twice a day; CX + T + VOR group). Control birds were implanted with T capsules only (CX + T group). CSB was almost completely blocked by injections of the aromatase inhibitor. The RCSM frequency decreased progressively in the CX + T + VOR group by comparison with the CX + T group and was therefore significantly reduced at the end of the experiment. These results demonstrate that the frequency of RCSM, a second measure of ASB is, like the social proximity response and CSB, blocked by inhibition of estrogen production. It was shown previously that lesions of the preoptic area inhibit both aspects of the appetitive sexual behavior (proximity response and RCSM). It is therefore, likely that both responses are controlled, like copulation, by aromatase-containing neurons of the preoptic area.     

Isolation and characterization of 11 polymorphic microsatellite loci in collared lizards (Crotaphytus collaris)

We identified 11 polymorphic microsatellite loci in collared lizards (Crotaphytus collaris). Polymorphism assessment in 512 individuals from 52 populations sampled across much of the species distribution revealed a fairly high degree of genetic diversity (six to 20 alleles per locus) and a wide range of average expected heterozygosity values (0.143–0.530). We found no evidence for linkage, very few deviations from HW expectation (two of 572 possible population/locus analyses) and thus no evidence for null alleles. There was a tendency for reduced polymorphism towards the northern periphery.     

Effect of dietary Vitamin E on the cloacal gland, foam and semen characteristics of male Japanese quail

This experiment was to investigate the effects of increasing the level of dietary Vitamin E (Vit. E) on cloacal gland size, foam production and semen characteristics of male Japanese quail (Coturnix coturnix Japonica). One hundred and eighty male Japanese quail chicks (day old) were randomly distributed to three dietary treatments for a period of 25 weeks. Each treatment comprised of three replicates each containing 20 chicks. The basal diet contained 15 IU Vit. E/kg and the two experimental diets were supplemented with 150 and 300 IU Vit. E/kg (diets T2 and T3, respectively). DL alpha-tocopherol acetate was used as the source of Vit. E. All chicks were provided feed and water ad libitum. Foam characteristics, in terms of frequency of foam discharge (24h), cloacal gland index and foam weight were significantly higher (P<0.05) in T2 group. Body weight, testes weight (left and right) and plasma testosterone concentrations did not differ significantly. Semen characteristics (semen volume, sperm motility, % live sperm, % hatchability and sperm concentrations) did not differ significantly (P>0.05). Percentages of abnormal and dead spermatozoa were significantly (P<0.05) lower and fertility was higher (P<0.05) in the T2 group. From this study, it can be concluded that moderate supplementation of dietary Vit. E may be beneficial for foam production, cloacal gland and improve the semen characteristics in male Japanese quail.     

Structure of the L1 protuberance in the ribosome

The L1 protuberance of the 50S ribosomal subunit is implicated in the release/disposal of deacylated tRNA from the E site. The apparent mobility of this ribosomal region has thus far prevented an accurate determination of its three-dimensional structure within either the 50S subunit or the 70S ribosome. Here we report the crystal structure at 2.65 A resolution of ribosomal protein L1 from Sulfolobus acidocaldarius in complex with a specific 55-nucleotide fragment of 23S rRNA from Thermus thermophilus. This structure fills a major gap in current models of the 50S ribosomal subunit. The conformations of L1 and of the rRNA fragment differ dramatically from those within the crystallographic model of the T. thermophilus 70S ribosome. Incorporation of the L1-rRNA complex into the structural models of the T. thermophilus 70S ribosome and the Deinococcus radiodurans 50S subunit gives a reliable representation of most of the L1 protuberance within the ribosome.     

Conflict over multiple-partner mating between males and females of the polygynandrous common lizards

The optimal number of mate partners for females rarely coincides with that for males, leading to a potential sexual conflict over multiple-partner mating. This suggests that the population sex ratio may affect multiple-partner mating and thus multiple paternity. We investigate the relationship between multiple paternity and the population sex ratio in the polygynandrous common lizard (Lacerta vivipara). In six populations the adult sex ratio was biased toward males, and in another six populations the adult sex ratio was biased toward females, the latter corresponding to the average adult sex ratio encountered in natural populations. In males the frequency and the degree of polygyny were lower in male-biased populations, as expected if competition among males determines polygyny. In females the frequency of polyandry was not different between treatments, and polyandrous females produced larger clutches, suggesting that polyandry might be adaptive. However, in male-biased populations females suffered from reduced reproductive success compared to female-biased populations, and the number of mate partners increased with female body size in polyandrous females. Polyandrous females of male-biased populations showed disproportionately more mating scars, indicating that polyandrous females of male-biased populations had more interactions with males and suggesting that the degree of multiple paternity is controlled by male sexual harassment. Our results thus imply that polyandry may be hierarchically controlled, with females controlling when to mate with multiple partners and male sexual harassment being a proximate determinant of the degree of multiple paternity. The results are also consistent with a sexual conflict in which male behaviors are harmful to females.     

Relationship of cloacal gland with testes, testosterone and fertility in different lines of male Japanese quail

An attempt has been made to investigate the relationship of cloacal gland with testes, testosterone and fertility in different lines of Japanese quail (Coturnix coturnix japonica). For this study, three lines of healthy adult male Japanese quails (<12 weeks) viz., heavy body weight (HB), white breasted (WB), and white egg shell (WES) were taken. They were housed in individual cages under uniform husbandry conditions and were provided with normal quail breeder ration and water ad libitum, with 14 h light/day. The experimental birds were selected from each of these three lines and categorized into different groups (15 birds/group) based on the increasing order of the area of cloacal gland. At the end of this experiment (24 weeks) the data indicated that size of the cloacal gland was directly proportional to foam discharge, foam weight, testicular weight, fertility and testosterone concentration in plasma. From this study it may be concluded that area of cloacal gland in Japanese quail is positively correlated with testicular weight, level of testosterone in plasma and fertility. Visual examination of cloacal gland and cloacal foam may provide a valuable non-invasive tool for predicting the fertilizing ability of individual male bird.     

Development and characterization of microsatellite DNA markers for the Alpine plant species Campanula thyrsoides

We isolated and characterized eight polymorphic microsatellite markers for the Alpine plant species Campanula thyrsoides (Campanulaceae). Number of alleles per locus ranged from six to 12 and the observed heterozygosity was between 0.529 and 0.900. Observed vs. expected heterozygote deficits were significantly different in one out of eight loci following Bonferroni's correction for multiple tests. We did not find evidence for linkage disequilibrium between locus pairs. The microsatellite markers are being used for the study of genetic variation and gene flow within and among populations of C. thyrsoides in the Swiss Alps.     

Isolation and characterization of microsatellite loci in the Alpine leaf beetle,Oreina elongata

For a study of local adaptations in the Alpine leaf beetle, Oreina elongata, we developed six microsatellite loci and screened them in 305 individuals from 13 populations. All markers were polymorphic with three to 15 alleles per locus. Average observed and expected heterozygosity values were 0.14 and 0.62, respectively. Four markers showed heterozygote deficiency and deviated significantly from Hardy–Weinberg expectations, indicating the presence of null alleles.     

Isolation and characterization of microsatellite loci for the collared pika (Ochotona collaris) and their cross-amplification in five other Ochotona species

We developed primers for eight polymorphic microsatellite loci isolated from the collared pika, Ochotona collaris, and also tested nine loci previously developed for the American pika, O. princeps, for use in O. collaris. Forty-six individuals from an O. collaris population in the southern Yukon were genotyped using all 17 loci. The average number of alleles per locus was six and the average observed heterozygosity was 0.59. All loci were tested for use in four Asian pika species and all but two loci amplified reliably in these species.     

Anatomical identification of glomeruli in the antennal lobes of the male sphinx moth Manduca sexta

Summary Computer-assisted neuroanatomical methods have been used to demonstrate unique identities of the glomeruli of the antennal lobes (ALs) in males of the sphinx moth Manduca sexta. The glomerular neuropil consists of the male-specific macroglomerular complex, which comprises two closely apposed bulky subunits, and 64±1 ordinary glomeruli arrayed in a shell around a central region of coarse neuropil. Computergenerated maps show the exact locations of all glomeruli and adjacent groups of neuronal somata in a constant Cartesian coordinate system, such that these can be accurately identified in any individual. The glomeruli belong to three classes according to the number and type of identification criteria they satisfy. The larger class comprises glomeruli (n=44) identified only in the computer-generated maps on the basis of their relative positions. The other two classes include glomeruli that were also identified in sections, either directly from their proximity to readily identifiable structures and their shape and size (n=10, including the labial-palp-pit-organ (LPO) glomerulus), or indirectly from their positions relative to the former (n=9). Two very small glomeruli were present in only one AL, demonstrating the existence of anomalous glomeruli, whereas another glomerulus had no homologue in both ALs of one individual. The true number of ordinary glomeruli (per male AL) was thus estimated to be 64. The uncertainty in delineating some glomeruli might affect this number without implying modification of the homologies proposed. The locations of tracts and cell groups, both within and near the AL, are also invariant with respect to glomeruli, as shown in the computer maps. The methods employed are general and might be useful to researchers in related fields. The results obtained call for more attention to the precise geometry of neural structures.