The potential for egg-guarding care in females of the damselfish, Dascyllus reticulatus, in the absence of uniparental male care.

Male damselfish typically demonstrate uniparental egg-guarding care in nature. Potential plasticity in sexual behavior has recently been reported in various teleost fish. To examine behavioral plasticity in parental care, we conducted aquarium experiments to explore the potential for egg-guarding care in the female damselfish, Dascyllus reticulatus.

A newly identified enzyme from Japanese common squid Todarodes pacificus has the ability to biosynthesize d-aspartate.

Amino acids exist in two chiral forms, namely L and D. Although l-amino acids are predominant in vivo, certain limited circumstances have reported the usage of d-amino acids. d-aspartate (Asp), among them, plays crucial physiological roles in living organisms and is biosynthesized from L-Asp by the enzyme named aspartate racemase (AspRase).

Molecular characterization of aspartylglucosaminidase, a lysosomal hydrolase upregulated during strobilation in the moon jellyfish, Aurelia aurita.

The life cycle of the moon jellyfish, Aurelia aurita, alternates between a benthic asexual polyp stage and a planktonic sexual medusa (jellyfish) stage. Transition from polyp to medusa is called strobilation. To investigate the molecular mechanisms of strobilation, we screened for genes that are upregulated during strobilation using the differential display method and we identified aspartylglucosaminidase (AGA), which encodes a lysosomal hydrolase.

Molecular cloning and expression profile of sex-specific genes, Figla and Dmrt1, in the protogynous hermaphroditic fish, Halichoeres poecilopterus.

The genes folliculogenesis specific basic helix-loop-helix (facor in the germline alpha, Figla) and doublesex and mab-3 related transcription factor 1 (Dmrt1) are female- and male-specific genes that play key roles in sex differentiation. To obtain a better understanding of the molecular mechanisms underlying female-to-male sex change, we cloned the cDNAs of these genes from an ovary and a testis of the protogynus wrasse, Halichoeres poecilopterus. This fish has two isoforms of Dmrt1, Dmrt1a and Dmrt1b, caused by an alternative splicing.

Indomethacin induction of metamorphosis from the asexual stage to sexual stage in the moon jellyfish, Aurelia aurita.

We found while screening a chemical library that indomethacin, an inhibitor of prostaglandin biosynthesis, induced strobilation (metamorphosis from the asexual to sexual stage) in the moon jellyfish, Aurelia aurita. Indomethacin initiated strobilation in a dose-dependent manner, but was not involved in the progression of strobilation. Pharmacological experiments suggested that indomethacin could induce strobilation independently of prostaglandin biosynthesis.

Examination of the ability of gonadal sex change in primary males of the diandric wrasses Halichoeres poecilopterus and Halichoeres tenuispinis: estrogen implantation experiments.

Primary males that function as males throughout their lives are often found among protogynous fishes such as wrasses and parrotfishes. However, the issue of whether the sexuality of primary males involves gonochorism or hermaphroditism remains uncertain. To clarify this, we implanted estradiol-17beta (E2) into the body cavities of primary males of two protogynous wrasses, Halichoeres poecilopterus and Halichoeres tenuispinis.

Cloning of full-length cDNA of teleost corticotropin-releasing hormone precursor by improved inverse PCR.

We designed a new inverse PCR protocol combined with switching mechanism at 5' end of RNA transcript (SMART) technology, and applied it to the cloning of teleost corticotropin-releasing hormone precursor cDNA. Due to the advantages of both techniques, this method can efficiently amplify the complete 5'- and 3'-ends of cDNA in a single reaction, and might prove to be an alternative to the conventional rapid amplification of cDNA ends (RACE) approaches.

Expression analysis of the lingerer gene in the larval central nervous system of Drosophila melanogaster.

The lingerer (lig) gene is necessary for initiation and termination of copulatory behavior in Drosophila melanogaster. The lig gene encodes cytoplasmic proteins, and is expressed in the central nervous system (CNS) during the late third-instar larval stage when the lig function is required for normal copulation to occur after adult eclosion. To characterize the lig-expressing cells in the late third-instar larval CNS, we have isolated a genomic fragment containing the promoter/enhancer region of the lig gene, and established transgenic lines in which expression of reporter genes is controlled by the lig promoter/enhancer.

Molecular cloning of the prothoracicotropic hormone from the tobacco hornworm, Manduca sexta.

A cDNA encoding a putative precursor of prothoracicotropic hormone (PTTH) from the tobacco hornworm, Manduca sexta, was isolated and sequenced. This clone contains an open reading frame encoding a 226-amino acid prepropeptide hormone. The deduced amino acid sequence is composed of a signal sequence, a precursor domain and a mature hormone and shows similarities to the other PTTHs that have been cloned from closely related lepidopteran species, Bombyx mori, Samia cynthia ricini, Antheraea peryni, and Hyalophora cecropia.

lingerer, a Drosophila gene involved in initiation and termination of copulation, encodes a set of novel cytoplasmic proteins.

In an effort to uncover genetic components underlying the courtship behavior of Drosophila melanogaster, we have characterized a novel gene, lingerer (lig), mutations of which result in abnormal copulation. Males carrying a hypomorphic mutation in lig fail to withdraw their genitalia upon termination of copulation, but display no overt abnormalities in their genitalia. A severe reduction in the dosage of the lig gene causes repeated attempted copulations but no successful copulations.

Molecular characterization of a novel nuclear transglutaminase that is expressed during starfish embryogenesis.

We report the constitution and molecular characterization of a novel transglutaminase (EC 2.3.2.