Drosophila FMR1 mutants are models of human fragile X syndrome. They show a loss of locomotor activity rhythm and severe degradation of eclosion timing. We analyzed the circadian behavior of FMR1 mutants (dfmr1^B55) in two genetic backgrounds, yellow white (yw) and Canton S (CS). The arrhythmic phenotype of circadian locomotor activity in constant darkness (DD) did not significantly change in either genetic background. Surprisingly, eclosion timing was completely restored by backcrossing dfmr1^B55 with yw or CS flies. Morphological analysis of the small ventrally located lateral neurons of FMR1 mutants revealed that the dorsal-projection area was significantly larger in arrhythmic than rhythmic flies. In addition, dfmr1^B55 mutants in both genetic backgrounds had a significantly lower evening peak in the light-dark (LD) cycle. These results indicate that lack of FMR1 does not affect eclosion timing, but alters locomotor activity patterns in both LD and DD conditions by affecting the arborization of small ventrally located lateral neurons. Thus, the FMR1 gene may regulate the circadian-related locomotor activity of Drosophila.

Many wrasses on coral reefs exhibit daily spawning that peaks around daytime high tides. In this study, we examined tidal-related ovarian development in the threespot wrasse, Halichoeres trimaculatus, a species common on coral reefs in the Indo-Pacific Ocean. When the fish were collected in the morning at different tidal phases, the gonadosomatic index (GSI) and ovarian histology changed; concomitant with increases in GSI towards high tide, a clutch of the most advanced oocytes developed from vitellogenic to maturation stages. Ovulated eggs and post-ovulated follicles (POF) existed in most ovaries around high tide, but only POF remained around ebb tide, suggesting that spawning occurred during or after high tide. We noticed that tidal-related spawning was considerable in the morning and that most ovaries collected on the afternoon high tide exhibited post-spawning features. This suggests that certain labrid species possess plasticity with regard to their spawning time and utilize potent environmental cues to ensure their reproductive success. When pieces of ovary were incubated with precursor steroids, high conversion of testosterone to 17β-estradiol occurred during high and ebb tides, while that of 17α-hydroxyprogesterone to 17α,20β-dihydroxy-4-pregnen-3-one and 17α,20β,21-trihydroxy-4-pregnen-3-one was observed during low and flood tides. Incubation of pieces of ovary with human chorionic gonadotropin resulted in similar fluctuations in the steroid hormones with tidal phase. Production of these steroid hormones correlated with oocyte development in the ovaries and was probably regulated by gonadotropin. These results demonstrate that the daily cycle is fundamental for oocyte development, and that the tidal cycle is superimposed on this process.

Lipid droplets are considered one of the most important energy sources in lepidopteran eggs during late embryogenesis, but the process of their incorporation into the embryo is as yet unknown. The present study focused on the process of transition of lipid droplets from the extraembryonic yolk to the embryo of the silkworm Bombyx mori, using morphological and biochemical approaches. The morphological study revealed that the incorporation of lipid droplets from the extraembryonic yolk into the embryo occurs at three points and in three different ways during the development of the embryo. Some lipid droplets were translocated directly from the extraembryonic yolk to the embryo before the blastokinesis stage. However, the majority of lipid droplets together with the other components of the extraembryonic yolk were incorporated in the embryo via both morphogenetic inclusion during dorsal closure and ingestion of the extraembyonic yolk by the developing caterpillar prior to hatching. Similar results were obtained from the biochemical study. Thus, we propose that there are three steps in the incorporation of lipid droplets from the extraembryonic yolk into the embryo. In addition, morphological and biochemical data concerning the total amount of lipid droplets in the egg suggested that lipid droplets were mainly consumed during late embryogenesis, seeming to synchronize with tracheal development.

The smooth newt (Lissotriton “Triturus” vulgaris) and Montandon’s newt (L.“T.” montandoni) are sister species exhibiting pronounced differences in male secondary sexual traits but nevertheless hybridizing and producing fertile hybrids in nature. Since pheromonal communication is an important aspect of the reproductive biology of urodeles, structural differentiation of peptide pheromones and their receptors may contribute to incipient reproductive isolation. The aim of the study was the identification of genes encoding putative courtship pheromone precursors in two newt species and the reconstruction of phylogenetic relationships among them. Our analyses were based on cDNA obtained from the transcripts from the abdominal glands of male newts. We identified five unique cDNA sequences encoding the putative pheromone precursors in L. vulgaris and three additional unique sequences in L. montandoni. The results indicate that in the abdominal glands of Lissotriton newts more than one pheromone-encoding gene is expressed and that these loci form a gene family. Phylogenetic analysis indicates that the divergence of at least some of these genes predates the radiation of European newts.

The diversity and spatiotemporal variation of avifauna in different settings of tropical coral reef-karst forests on the Hengchun Peninsula, Taiwan, were examined. The short-term effects on bird assemblages following two typhoons that severely impacted Hengchun were investigated. Line-transect census recorded 46 species of birds, dominated by forest-associated gleaning insectivores or omnivores, and 13% of the endemics of Taiwan. Prior to the typhoons, the continuous-canopy forest was close to the open forest setting in species evenness, but the species heterogeneity was lower and more variable. The continuous-canopy and open forests differed in overall avian composition, whereas two continuous-canopy forest settings were similar in composition. Typhoons did not significantly lower the mean numbers of either species or birds, nor affect the pattern of their spatial distribution in the forest settings. However, they did increase similarities in the species composition between the open and continuous-canopy settings, and caused a decrease in the similarity between forest edges and interiors. Overall, typhoons affected species composition more in the continuous-canopy forests than in the open setting, and more in interiors than in forest edges. This pattern corresponded to an increase in the species heterogeneity and species evenness in the forest interiors, indicating movements of birds from the edge toward the interior. Among different functional groups, gleaning omnivores tended to retain a pattern of higher abundance in the open forest setting than in the continuous-canopy forests, whereas the abundances of gleaning insectivores and cavity-nesting frugivores tended to decline in the latter or both settings.

Dogfish (Squalus acanthias) growth hormone (GH) was identified by cDNA cloning and protein purification from the pituitary gland. Dogfish GH cDNA encoded a prehormone of 210 amino acids (aa). Sequence analysis of purified GH revealed that the prehormone is composed of a signal peptide of 27 aa and a mature protein of 183 aa. Dogfish GH showed 94% sequence identity with blue shark GH, and also showed 37–66%, 26%, and 48–67% sequence identity with GH from osteichtyes, an agnathan, and tetrapods. The site of production was identified through immunocytochemistry to be cells of the proximal pars distalis of the pituitary gland. Dogfish GH stimulates both insulin-like growth factor-I and II mRNA levels in dogfish liver in vitro. The dogfish GH gene consisted of five exons and four introns, the same as in lamprey, teleosts such as cypriniforms and siluriforms, and tetrapods. The 5’-flanking region within 1082 bp of the transcription start site contained consensus sequences for the TATA box, Pit-1/GHF-1, CRE, TRE, and ERE. These results show that the endocrine mechanism for growth stimulation by the GH-IGF axis was established at an early stage of vertebrate evolution, and that the 5-exon-type gene organization might reflect the structure of the ancestral gene for the GH gene family.

Zebrafish (Danio rerio) were used as a model fish, and the technique of RNA interference (RNAi) was employed to knockdown three subunits of the gonadotropin alpha (GtHα, common α), follicle-stimulating hormone beta (FSHβ), and luteinizing hormone beta (LHβ) genes. Three short-hairpin RNA (shRNA) expression vectors and three mismatched shRNA expression vectors as controls for each subunit gene were constructed, and the depression efficiency was tested in vivo by microinjection; the RNA or protein expression levels of the GtH genes were monitored by RT-PCR, Southern blotting, and green fluorescent protein (GFP) analyses. Expression of GtH mRNA was obviously and more efficiently depressed by GtHα RNAi expression compared with the other two subunits. A GtHα morpholino analysis showed that the GtHα morpholino led to suppression of embryonic development and the production of embryonic mutants as a result of an injection of GtHα -shRNA. Taken together, these results show that GtHα-shRNA, which more efficiently targets RNAi, may have an essential role in the further development of sterility technology of transgenic fish for biosafety purposes.

Though sequences of formation and ossification of bony elements have been described for many taxa, controversy surrounds the formation of limb elements in turtles. Three hypotheses for patterns of formation of autopodial elements have been proposed, differing primarily in the origin of Distal Carpal/Tarsal 3, the digital arch, and Centrale 4. Patterns of formation and ossification of limb elements are described for Trachemys scripta. These patterns are compared to similar data for representatives of four families of turtles (Cheloniidae, Chelydridae, Emydidae, and Trionychidae). Hypotheses of limb formation are compared in the context of new and published data. Three species (Trachemys scripta, Chrysemys picta, and Chelydra serpentina) suggest that Distal Carpal 3 forms by branching from the ulnare, whereas Distal Carpal 3 may branch from Distal Carpal 4 in Macrochelys temminckii and Chelonia mydas; data from Graptemys nigrinoda, Apalone spinifera, and Eretmochelys imbricata did not provide evidence for the origin of Distal Carpal 3. Centrale 4 was not observed to branch from the ulnare and apparently arises by de-novo condensation. Distal Carpal 4 did not branch from Centrale 4 in any species. Until the developmental origins of Distal Carpal 3 and Centrale 4 are understood, interspecific variation in the origin of these elements remains, and may explain some of the observed differences. Trends of ossification in the fore- and hind limb autopodium also are summarized. Homology of elements in pedal Digit V is discussed, and we suggest that the hooked proximal element of this digit be recognized as Distal Tarsal 5.

Morphological characteristics of the lateral line receptors, specifically the superficial neuromast, the pit organ, and the ampullary organ, are described and compared among larval, metamorphosed, and both female and male adult Hynobius leechii. The distribution and morphologies of the lateral line receptors are similar to those of other urodeles. During the transition from a larval to an adult salamander, the number of receptors is generally reduced, but their sizes increase. Other morphological changes also occur, such as the development of a more distinct mantle cell boundary at the epidermal surface of the adult ampullary and pit organs. In particular, we found kinocilia on the sensory hair cells of the ampullary organs of both larval and adult salamanders, and, for the first time, we describe two different morphologies of the pit organ in urodeles. The detailed description of the pit organ represents only the second study of its kind in urodeles. However, our comparison of lateral line receptors between larval and adult salamanders is the first of its kind for salamanders that utilize external fertilization.

The effects of rearing conditions on the functional recovery of wind-sensitive giant interneurons (GIs) after unilateral cercal ablation were investigated in the cricket, Gryllus bimaculatus. Crickets were reared in a glass vials to prohibit free walking for 14 days after unilateral cercal ablation (“14-day vial” crickets). Other crickets were reared in an apparatus called a “walking inducer” (WI) to increase the walking distance during the same 14-day period (“14-day WI” crickets). In these crickets, the response properties of GIs 8-1, 9-1, 9-2, and 9-3 to air currents from various directions were investigated. From the intensity-response curves obtained, directionality curves expressed in terms of threshold velocity and response magnitude were made independently. To understand changes in the functional recovery of GIs more thoroughly, the directional characteristics of GIs in crickets 1 day after unilateral cercal ablation (“1-day free” crickets) were also compared. Between the 1-day free and 14-day vial crickets, all the GIs showed differences in both threshold velocity and response magnitude for some stimulus directions. Between the 14-day vial and 14-day WI crickets, differences in the threshold velocities of GIs 9-1, 9-2, and 9-3, and in the response magnitudes of GIs 8-1, 9-1, and 9-3 were detected. Because the rearing condition after unilateral cercal ablation largely affects the compensatory recovery in some parameters of wind-evoked escape behavior, such as relative occurrence and escape direction, we discuss the functional differences in GIs revealed here in relation to the roles of GIs in the neural system that controls escape behavior.

Mustelidae is the largest and most diverse family in the order Carnivora. The phylogenetic relationships among the subfamilies have especially long been a focus of study. Herein we are among the first to employ two new introns (4 and 7) of the nuclear β-fibrinogen gene to clarify these enigmatic problems. In addition, two previously available nuclear (IRBP exon 1 and TTR intron 1) and one mt (ND2) data sets were also combined and analyzed simultaneously with the newly obtained sequence data in this study. Detailed characterizations of the two intronic regions not only reveal the remarkable occurrences of short interspersed element (SINE) insertion events, providing a new example supporting the attractive hypothesis that attrition of an earlier retroposition may offer a proper environment for successive retropositions by forming a “dimer-like” structure, but also demonstrate their utility in the resolution of mustelid phylogeny. All of our analyses confirm the assemblage of Mustelinae, Lutrinae, and Melinae with confidence; moreover, two clades within Mustelinae were clearly recognized, i.e., genera Mustela and Martes. Notably, genus Martes of Mustelinae was found to branch off first, followed by Melinae and then a clade containing Lutrinae and genus Mustela of Mustelinae, indicating paraphyly of Mustelinae. In addition, Mephitinae diverges before the other mustelids and the monophyletic Procyonidae in all cases, supporting its elevation to a separate family. Additional independent genetic markers are still in need to resolve the trichotomy among Mephitinae and the other two carnivoran clades, Ailuridae and Procyonidae/non-mephitine Mustelidae.

The genus Miridiba is here reviewed on the basis of external morphological and genital characters. This genus now contains 27 species, eight of which are new transfers from Holotrichia Hope, 1837; Holotrichia (Pledina) Reitter, 1901; Melolontha Fabricius, 1775; and Neodontocnema Arrow, 1948. A type series of thirteen species is designed. Hippotrichia Arrow, 1948 and Neodontocnema are described in detail.

The karyotypes of three rat species from Hainan Island, China, were examined. Niviventer fulvescens (Gray, 1847) had 2n=46 and FN=64, similar to the karyotypes reported for N. fulvescens from Southeast Asia, while Niviventer lotipes (Allen, 1926) had 2n=52 and FN=66, which is distinct from the known karyotypes of other Niviventer species. Niviventer lotipes was recently considered conspecific with N. tenaster (Thomas, 1916), but the two were found to have extremely different karyotypes (2n=52 and FN=66 in N. lotipes; 2n=46 and FN=54 in N. tenaster). Therefore, in this paper N. lotipes is considered a valid species for the first time; it is distinct from N. tenaster and endemic to Hainan Island, where N. lotipes is differentiated from N. fulvescens by larger body and skull sizes, a shorter tail, and darker coloration. Rattus nitidus (Hodgson, 1845) from Hainan Island had 2n=42 and FN=62, which is similar to the reported karyotypes of conspecific populations in Southeast Asia.