This study was designed to evaluate the ability of mice to discriminate cow urinary odor from different reproductive phases, with a view toward detecting the estrous phase. Experiments were also carried out to establish the relationship between androgen and mouse behaviors during estrous detection. Further, the study was also intended to establish the relationship between androgen and behaviors in estrous detection. Bovine urine was collected during estrus and non-estrous periods, i.e., prepubertal, preovulatory, ovulatory, postovulatory, pregnancy, and lactation. Behavioral analyses were carried out in a Y-maze apparatus, in which the mice were acclimatized in before odor-preference tests. The number and duration of visits, and grooming behavior by male responders towards the urine samples, were recorded. Intact male mice showed a higher response towards estrus urine samples than towards non-estrous urine. By contrast, orchidectomized mice failed to discriminate estrous urine, whereas castrated mice treated with testosterone regained the ability to discriminate estrus odor. A higher level of grooming behavior was found in males exposed to estrous urine than to urine of other phases. These results suggest that normal mice have the ability to detect estrus, and that this discriminating ability is androgen dependent. The grooming behavior shown by males in response to estrous urine may be taken as a key parameters in estrous detection. The results further suggest that bovine estrous urine produces specific odors that probably involve both intraspecific and interspecific communication.

Morphological asymmetry and behavioral laterality in vertebrate species have been intensively studied in recent years, while comparable invertebrate studies are rare. Here we demonstrate asymmetry in the curvature of the abdomen and laterality in evasive responses for two atyid shrimps, Limnocaridina latipes and Neocaridina denticulata. The frequency distributions of the angle of the abdominal curvature in both species were discretely bimodal, suggesting that the two populations are composed of both left- and right-type individuals. In N. denticulata, behavioral analysis using high-speed filming illustrated that the escape direction for each individual, evoked by a sudden non-lateralized stimulus, was correlated with its abdominal curvature: left- (right-) type shrimp jumped back-leftward (−rightward) significantly more than often. A crossing experiment with N. denticulata indicated that the trait frequency in the F1 generation from two left-type parents differed significantly from that of the F1 generation from two right-type parents, and that the trait frequency for the F1 generation from parents of different laterality types did not deviate from random. That is, offspring laterality type is affected by the lateralities of the parents, indicating that abdominal dimorphism in shrimp is genetically derived. These results suggest that shrimp have an innate laterality that controls their escape direction, which in turn may affect prey-predator interactions in the aquatic community.

Siboglinid worms live on carbohydrates produced by symbiotic bacteria. In this study, α-glucosidase-like activity was detected in the surface of the body and in the trophosome of Oligobrachia mashikoi. The enzyme exhibiting this activity was partially purified by consecutively applying the crude enzyme extract to Con-A-Sepharose and Sephadex-200 HR columns. The enzyme sample thus obtained gave a single activity peak at a position corresponding to 550 kDa in the Sephadex-200 HR gel filtration column. The enzyme was active in the range of pH 6.0–8.0, with a maximum activity at around pH 6.5. It specifically hydrolyzed maltose, and was inhibited by voglibose and miglitol. Moreover, a glucose transporter 2-like protein was detected by immunohistochemical and Western-blotting analyses using anti-rat GLUT2 polyclonal antibody. These results raise the question how this unique species lives.

The white-nest swiftlet, Aerodramus fuciphagus, originally lived in large colonies in natural caves, but now it also occurs in man-made buildings. We investigated the patterns of genetic differentiation in two mitochondrial DNA genes (cyt-b and ND2) and eight microsatellite loci among and within colonies of A. fuciphagus from across recently established man-made colonies in Thailand. Ten white-nest swiftlet colonies were sampled along the coast of the Gulf of Thailand and the Andaman Sea in Thailand during 2003–2006. The genetic diversity of mtDNA was very low, and few significant Φ_ST values were found between pairs of colonies. Analyses of haplotype relationships did not show genetic structure across the sampled distribution. The level of genetic diversity for microsatellite loci was high, but FST values were not significant. However, due to small sample sizes for some colonies that could limit conclusions on genetic differentiation from Φ_ST and F_ST, we also analyzed the microsatellite data using STRUCTURE and found that number of subpopulations of white-nest swiftlets in sampled colonies was one. The lack of genetic differentiation among swiftlet house colonies could be a result of high gene flow between colonies and large population sizes. Our results suggest that A. fuciphagus living in recently established man-made colonies in Thailand should be considered members of a single panmictic population. Future work will be necessary to determine whether this panmixia is stable or a temporary result of the recent explosive expansion of the number of colonies, and comparisons to natural colonies may provide an understanding of mechanisms producing the lack of genetic structure in swiftlet house colonies.

To clarify the genetic divergence in the F. limnocharis complex from Thailand and neighboring countries and to elucidate the phylogenetic problems of this taxon, we analyzed partial sequences of the mitochondrial 12S and 16S rRNA genes and the nuclear CXCR4, NCX1, RAG-1, and tyrosinase genes. The F. limnocharis complex from Thailand had three distinct haplotypes for 12S and 16S rRNA genes. Nucleotide similarities and the phylogenetic relationships indicated that the haplotype 1 group corresponded to the real “F. limnocharis”, the haplotype 2 group was F. orissaensis or closely related to it, and the haplotype 3 group was possibly an undescribed species. Mitochondrial gene data also showed two major clades of the genus Fejervarya, the Southeastern and South Asian groups. Although F. orissaensis is so far known only from Orissa in India, the haplotype 2 group was observed in Thailand. This distribution pattern and the phylogeny suggested that the origin of F. orissaensis and the haplotype 2 group might lie in Southeast Asia. There was also evidence suggesting that the haplotype 3 group originated in the South Asian area and has spread to northern Thailand. The nuclear gene data did not support the monophyly of the haplotypes recognized by mitochondrial genes. This incongruence between the mitochondrial and nuclear data seems to be caused by ancestral polymorphic sites contained in nuclear genes. Although neither the mitochondrial nor the nuclear data clarified intergeneric relationships, the nuclear data rejected the monophyly of the genus Fejervarya.

Genetic diversity and genetic divergence were investigated in the landlocked goby Rhinogobius sp. YB by analysis of seven microsatellite DNA loci and the mtDNA control region sequence, and were compared with those of the closely related amphidromous species Rhinogobius sp. DA. Samples of Rhinogobius sp. YB and Rhinogobius sp. DA were collected from seven and four rivers, respectively. All pairwise F_st tests based on microsatellite DNA showed significant genetic differences, except for one pair of populations of Rhinogobius sp. DA (P<0.00064, α=78). The average Nei's genetic distance was 0.616 in Rhinogobius sp. YB and 0.394 in Rhinogobius sp. DA. Forty-two haplotypes were detected in both species, and almost all Rhinogobius sp. YB populations included different haplotypes. The means of allelic richness, H_o, and H_e in Rhinogobius sp. YB (2.057, 0.149, and 0.156, respectively) were significantly lower than in Rhinogobius sp. DA (4.868, 0.366, and 0.403, respectively; P<0.05). The high genetic divergence and low genetic diversity in Rhinogobius sp. YB may have resulted from repeated colonizations of rivers by different founders. Efforts to conserve genetic resources should take these evolutionarily significant units (ESU) of Rhinogobius sp. YB into account. The genetic markers used in this study provide simple and highly informative indicators for Rhinogobius sp. YB population management.

Microorganisms dwell symbiotically in the termite hindgut. In this study, we identified genes that contribute to the role of the host in maintaining this symbiotic relationship with microorganisms. Body tissue and digestive organs (salivary gland, foregut, midgut, and hindgut) dissected from the lower termite Hodotermopsis sjostedti were used for the analyses. The transcriptomes in these organs were investigated using expressed sequence tag (EST) analysis. The cDNA libraries from the salivary gland and foregut included not only cellulase genes, but also several genes involved in glucose production, heme-cellulose degradation, chitin degradation, the innate immune system, and anti-microbial activity. We compared the expression level of these genes in the organs and body by real-time quantitative RT-PCR. Real time RT-PCR analyses confirmed that the genes associated with cellulose degradation, innate immunity, and anti-microbial proteins are much more strongly expressed in the salivary gland than in other tissues. Our results identify functional genes used by the host in the termite symbiotic system.

The cerebellar structures of teleosts are markedly different from those of other vertebrates. The cerebellum continues rostrally into the midbrain ventricle, forming the valvula cerebelli, only in ray-finned fishes among vertebrates. To analyze the ontogenetic processes that underlie this morphological difference, we examined the early development of the cerebellar regions, including the isthmus (mid/hindbrain boundary, MHB), of the medaka (Oryzias latipes), by histology and in-situ hybridization using two gene (wnt1 and fgf8) probes. Isthmic wnt1 was expressed stably in the caudalmost mesencephalic region in the neural tube at all developmental stages examined, defining molecularly the caudal limit of the mesencephalon. The wnt1-positive mesencephalic cells became located rostrally to the isthmic constriction at Iwamatsu's stages 25–26. Isthmic fgf8 expression changed dynamically and became restricted to the rostralmost metencephalic region at stage 24. The rostralmost part (prospective valvula cerebelli) of the fgf8-positive rostral metencephalon protruded rostrally into the midbrain ventricle, bypassing the isthmic constriction, at stages 25–26. Thus, the isthmic constriction shifted caudally with respect to the molecularly defined MHB at stages 25–26. Paired cerebellar primordia were formed from the alar plates of the fgf8-positive rostral metencephalon and the fgf8-negative caudal metencephalon in the medaka neural tube. Our results show that cerebellar development differs between teleosts and murines: both the rostral and caudal metencephalic alar plates develop into the cerebellum in medaka, whereas in the murines only the caudal metencephalic alar plate develops into the cerebellum, and the rostral plate is reduced to a thin membrane.

By intracellular recordings, we studied the effects of pH buffering on the size of the receptive field and the extent of dye coupling of horizontal cells (HCs) in the light-adapted carp retina. These parameters were compared between data obtained in fortified Ringer's solution and those obtained in control bicarbonate Ringer's of the same pH (7.60). In Ringer's fortified with 10 mM HEPES or 15 mM Tris, the dye-coupling ratio of HCs increased by 71% and 70%, respectively. These fortified Ringer's solutions also depolarized the dark membrane potential and increased the light-evoked response. The HC receptive field profile could be described by the exponential decline in peak response amplitude to a slit of light moved tangentially from the recording electrode. Thus, the receptive field size was determined as a space constant proportional to (g_j/g_m)^1/2, where g_j and g_m denote gap and non-gap-junctional conductances. The HEPES- or Tris-fortified Ringer's significantly increased the space constant by 43% and 41%, respectively. Since dye coupling was increased in the fortified Ringer's, it is likely that g_j increased more than g_m as a result of alkalinization of the cytosol. Since HEPES has an aminosulfonate moiety, it has been assumed to close the hemi-channels of connexin 26, but the pH-buffering effects were essentially the same as those of Tris that has no aminosulfonate moiety. Therefore, it is unlikely that the closure of connexin 26 hemichannels is responsible for the change in the receptive field size of HCs.

Ovarian low density lipoproteins (LDL) such as vitellogenin (Vg) are the precursors of the major yolk protein vitellin, and constitute the major source of nutrients serving the developing embryo. The objective of this study was to gain a better understanding of crustacean egg development by focusing on the process of Vg internalization by its receptor (ovarian LDLR). First, an ovarian LDLR cDNA sequence in Marsupenaeus japonicus was determined. Ovarian LDLR mRNA expression was then examined, and was seen to be specific to the ovary, exhibiting highest levels during the previtellogenic stage. This pattern of ovarian LDLR expression is thought to signify preparation for yolk protein incorporation into the oocyte. Using immunoblotting techniques, an ovarian LDLR band was detected whose size was similar to that estimated from the deduced amino acid sequence. The ovarian LDLR protein was expressed only at the onset of vitellogenesis, and histological studies supported these observations. This is the first occasion that the ovarian LDLR and its expression dynamics during vitellogenesis have been fully characterized in a crustacean.

A new species of the Rhinolophus philippinensis group (Chiroptera: Rhinolophidae) is described from Guangdong, Guangxi, and Jiangxi Provinces in China. Rhinolophus huananus n. sp. is characterized by the horseshoe, as well as by external and cranial characteristics that separate it at the species level from the other members of the philippinensis group. One of the small species of the philippinensis group, R. huananus is intermediate in size between smaller R. siamensis and larger R. macrotis.

A new genus, Ceratotingis, distributed in Central America, is described to accommodate two new species, C. rafaeli from Panama and C. costarriquense from Costa Rica and to include Macrotingis zeteki from Panama. This paper includes descriptions of the new genus and its species, a redescription of C. zeteki, an identification key, and habitus photographs.

A new species, Bruchidius paicus (Insecta, Coleoptera) reared from the seeds of a leguminous tree, Albizia lebbeck (Fabaceae: Mimosoideae: Ingeae), is described from Northern Thailand. Inspection of genital and external morphological traits of B. paicus revealed that the new species belongs to Bruchidius Group 5 (sensu Chûjô, 1937). The definition of Group 5 is reviewed based on both external and genital morphology. Further comparison of the group to molecular Clade I of Bruchidius (sensu Kergoat, 2007a) indicates the two groups correspond to each other.