Glycosyltransferases (GTs) catalyse the reaction of glyco‐conjugation of various biomolecules by transferring the saccharide moieties from an activated nucleotide sugar to nucleophilic glycosyl acceptor. In insects, GTs show diverse temporal and site‐specific expression patterns and thus play significant roles in forming the complex biomolecular structures that are necessary for insect survival, growth and development. Several insects exhibit GT‐mediated detoxification as a key defence strategy against plant allelochemicals and xenobiotic compounds, as well as a mechanism for pesticide cross‐resistance. Also, these enzymes act as crucial effectors and modulators in various developmental processes of insects such as eye development, UV shielding, cuticle formation, epithelial development and other specialized functions. Furthermore, many of the known insect GTs have been shown to play a fundamental role in other physiological processes like body pigmentation, cuticular tanning, chemosensation and stress response. This review provides a detailed overview of the multifaceted functionality of insect GTs and summarizes numerous case studies associated with it.

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Mitochondrial dynamics (fusion and fission) has been demonstrated to necessary for stem cell maintenance and differentiation, however, the relation between mitophagy, mitochondrial dynamics and stem cell exhaustion is not clearly understood. Here we report the multifaceted role of Atg1 in mitophagy, mitochondrial dynamics and stem cell maintenance in female germline stem cells (GSCs) in Drosophila. We found that depletion of Atg1 in GSCs leads to impaired autophagy (mitophagy) as measured by reduced formation of autophagosomes, increased accumulation of p62/Ref(2)P and accumulation of damaged mitochondria. We observed increased generation of mitochondrial reactive oxygen species (mROS) in GSCs with depleted Atg1 and mitochondrial clustering/fusion in cysts with Atg1 knockdown (Atg1KD). The mitochondrial clustering/fusion observed in Atg1KD cysts was due to increase in Marf levels and the mitochondrial phenotype could be rescued by overexpression of Drp1 or by depleting Marf via RNAi in Atg1KD cyst cells. Interestingly, double knockdown of both Atg1:Drp1and Atg1:Marf affected ovariole size, number of GCs and the number of vitellogenic oocytes. Strikingly, Atg1:Marf double knockdown leads to loss of GSCs, differentiated GCs and a total loss of vitellogenic stages suggesting block in oogenesis. Overall, our results demonstrate that Drp1, Marf and Atg1 function together to influence female germline stem cell maintenance and differentiation of cystoblasts into cysts.