Identification of tarsal-less peptides from the silkworm Bombyx mori

Abstract

The polycistronic and non-canonical gene tarsal-less (tal, known as pri) was reported to be required for embryonic and imaginal development in Drosophila; however, there are few reports of the tal gene in the silkworm Bombyx mori. Here, we cloned a tal-like (Bmtal) gene, and a sequence analysis showed that the Bmtal cDNA (1661 bp) contains five small open reading frames (smORFs) (A1, A2, A3, A4, and B) that encode short peptides of 11-12 (A1-A4) amino acid residues containing an LDPTG(E)L(Q)(V)Y motif that is conserved in Drosophila Tal, as well as a 32-amino-acid B peptide. Reverse transcription-quantitative polymerase chain reaction showed that the expression of the Bmtal gene was highest in the trachea, followed by the silk gland and Malpighian tubule, in day 3 fifth-instar larvae. Subcellular localization showed that BmTal localized in the nucleus. By regulating the expression of the full-length Bmtal gene and the functional smORFs of Bmtal, we showed that the expression levels of the Bmovo gene and genes related to the Notch, transforming growth factor-β, and Hippo signaling pathways changed with changes in BmTal peptide expression. A co-immunoprecipitation assay showed that BmTal interacts with polyubiquitin, which triggered degradation and/or processing of the 14-3-3 protein zeta. A comparative transcriptome analysis showed that 2843 (2045) genes were up- (down)-regulated after Bmtal gene expression was up-regulated. The up- (down)-regulated differentially expressed genes were enriched in 326 (278) gene ontology terms (P ≤ 0.05) and 54 (59) Kyoto Encyclopedia of Genes and Genomes pathways (P ≤ 0.05), and the results indicated that the BmTal peptides could function as mediators of hormone levels or the activities of multiple pathways, including the peroxisome proliferator-activated receptor, Hedgehog, mitogen-activated protein kinase, adipocytokine, and gonadotropin-releasing hormone signaling pathways, as well as the innate immune response. These results increase our understanding of the function and mechanism of BmTal at the genome-wide level.

Multiple Roles of the Polycistronic Gene Tarsal-less/Mille-Pattes/Polished-Rice During Embryogenesis of the Kissing Bug Rhodnius prolixus

“…In situ hybridization analysis of the Rp-mlpt gene during embryonic development shows a complex pattern of spatial expression, similarly to previously reported expression patterns in beetles, fruit flies, and other holometabolous insects (Savard et al, 2006;Galindo et al, 2007;Cao et al, 2018;Jiménez-Guri et al, 2018;Zhu et al, 2018;Ray et al, 2019). Most differences in expression have been observed in early developmental stages.…”

“…While bioinformatic studies point to hundreds or thousands of genes containing putative smORFs, only a few functional studies have been performed. In insects, the function of the smORF founding member mille-pattes (mlpt) was only investigated in detail in holometabolous insects, such as the D. melanogaster and T. castaneum (Savard et al, 2006;Galindo et al, 2007;Kondo et al, 2007), and more recently in basally branching Diptera (Jiménez-Guri et al, 2018) and Lepidoptera (Cao et al, 2018). In T. castaneum, mlpt acts as a gap gene during the process of embryonic segmentation, regulating Hox genes and thoracic vs. abdominal specification; knockdown of mlpt leads to embryos with multiple legs, mille-pattes in French (Savard et al, 2006).…”

A palmitoyltransferase Approximated gene Bm‐app regulates wing development in Bombyx mori

“…In Drosophila, the existence of the Hippo pathway coordinates multiple physiological processes, including developmental patterning, proliferation, apoptosis and cell growth, to regulate overall organ size (Boggiano & Fehon, 2012;Enderle & McNeill, 2013;Hariharan, 2015). In B. mori, all key components of the Hippo pathway exist (Liu et al, 2016; and genes involved in the Hippo pathway are particularly enriched in sev-eral mitotic tissues, including the ovary, testis and wing disc in B. mori Cao et al, 2018). In the current study, although expressions of Ds and Ft did not show significant alteration, the Hippo kinase cassette genes Hippo, Warts and Mats, which play a part for inhibiting excessive cell proliferation, were significantly up-regulated.…”

Multiple roles of the polycistronic genetarsaless/mille-pattes/polished-riceduring embryogenesis of the kissing bugRhodnius prolixus

“…The 3D structures of MLPTs (Dmel-pptd1 and 4) were predicted via CABS-dock and I-Tasser [48], respectively; Rprol-pptd1 and 2, both via CABS-dock. The global and local stereochemical quality of all predicted models were performed via Rampage [49], Verify3D [50], ProSA [51], VoroMQA [52], ProQ3D [53], Qprob [14], DeepQA [54] and SVMQA [55]. The most suited structural models were refined via ModRefiner [56].…”

“…While bioinformatic studies point to hundreds or thousands of genes containing putative smORFs, only a few functional studies have been performed. In insects, the function of the smORF founding member mlpt was only investigated in detail in holometabolous insects such as the D. melanogaster and T. castaneum [4; 5; 6] and more recently in basally branching Diptera [13]and Lepidoptera [14]. In T. castaneum mlpt acts as a gap gene during the process of embryonic segmentation, regulating Hox genes and thoracic versus abdominal specification; knockdown for mlpt leads to embryos with multiple legs, mille-pattes in French [6].…”