Shuang Xue

The unique mating behavior of Bittacidae has been extensively studied, yet the mechanisms underlying internal sperm transport and temporary storage before mating remain enigmatic. Herein, we aim to elucidate these mechanisms by investigating the fine structure of the ejaculatory duct, which serves for sperm transport and temporary storage. The ultrastructure of the ejaculatory duct of Terrobittacus implicatus (Mecoptera: Bittacidae) was examined by light and transmission electron microscopy for the first time in this study. The ejaculatory duct is composed of a median duct and a pair of symmetrical accessory sacs. In the proximal fifth portion, the two accessory sacs encompass the median duct in two loose layers. In the remaining distal portion, the median duct remains centrally positioned, and two accessory sacs symmetrically enclose its lateral and ventral surfaces. The distal median duct consists of a basal lamina, an unevenly arranged epithelium, a large subcuticular cavity, and a narrow inner cuticle. The distal accessory sac can be divided into three areas with distinct ultrastructural features. The ejaculatory duct exhibits conspicuous secretory activity, and given the absence of an ectodermal accessory gland in males, it is possible that the ejaculatory duct may fulfill additional glandular function. The narrow lumen and the reduced muscular sheath of the ejaculatory duct may be associated with the unique mechanism of ejaculation and mating.

ZF-HD (zinc finger-homeodomain) gene family plays important roles in plant growth, development, and various stress responses. In the present study, 49, 50, 22, and 32 ZF-HD genes were identified in Gossypium hirsutum, Gossypium barbadense, Gossypium arboretum, and Gossypium raimondii genomes, respectively. According to their phylogenetic features, the ZF-HD genes were classified into six groups. Segmental duplication, whole genome duplication, and transposable elements provides major forces for the expansion of cotton ZF-HD gene family during the divergence of Gossypium species and the divergence between monocots and dicots. The Ka/Ks ratios of the ZF-HD segmental duplication pairs were mainly distributed around 0.12, which indicated that they have experienced strong purifying selective pressure during evolution. Transcriptome analysis showed that 6 Gossypium hirsutum and 4 Gossypium barbadense ZF-HD genes were expressed in all tested tissues. Further, expression profiles under abiotic stress exhibited that the ZF-HD genes were differentially regulated in response to various stresses. Taken together, our findings provide a valuable information on the characterization of ZF-HD gene family and lay foundation for their further function investigations in cotton.

Macdunnoughia hybrida is a polyphagous herbivorous moth within the family Noctuidae. In this study, we sequenced and analyzed the complete mitochondrial genome (mitogenome) of M. hybrida. This mitogenome was 15,382 bp long and encoded 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and two ribosomal RNA unit genes (rRNAs). Except for cox1 started with CGA, all other PCGs started with the standard ATN codons. Most of the PCGs terminated with the stop codon TAA, whereas cox1, cox2 and nad4 end with the incomplete codon T−−. The whole mitogenome exhibited heavy AT nucleotide bias (80.7%). Gene order was conserved and identical to most other previously sequenced Noctuidae. Phylogenetic analysis positioned M. hybrida in a well-supported clade with Diachrysia nadeja and three Ctenoplusia species. The relationships (Catocalinae + (Plusiinae + (Acronictinae + (Heliothinae + (Amphipyrinae + (Hadeninae + Noctuinae)))))) were supported within Noctuidae.

Ctenoplusia albostriata is a pest of composite plants such as Calendula officinalis L. and Dahlia pinnata. In this study, we sequenced and analyzed the complete mitochondrial genome (mitogenome) of C. albostriata. This mitogenome was 15,284 bp long and encoded 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and 2 ribosomal RNA unit genes (rRNAs). Gene order was conserved and was found to be identical to most other previously sequenced Noctuidae. The whole mitogenome exhibited heavy AT nucleotide bias (80.9%). Except for cox1 started with CGA, all other PCGs started with the standard ATN codons. Most of the PCGs terminated with the stop codon TAA, whereas cox1, cox2 and nad4 end with the incomplete codon T––. Phylogenetic analysis showed that the mitogenome of C. albostriata was similar to C. agnata and C. limbirena, and the subfamily Plusiinae was close to Acronictinae, Heliothinae, Amphipyrinae, Noctuinae, and Hadeninae.