Cis-acting elements, CArG-, E-, CCAAT- and TATA-boxes may be involved in sexually regulated gene transcription in Schistosoma mansoni

Abstract

Schistosomes undergo various morphological and metabolic changes during their development, reflected in a finely tuned regulation of protein and/or gene expression. The mechanisms involved in the controlKey words: Schistosoma mansoni -transcription -promoter -nuclear extract -gel shift analysis During its life cycle, Schistosoma mansoni undergoes a large number of morphological and metabolic changes, dictated mainly by the constraints imposed by the radically different environments associated with each developmental stage. Schistosomes develop from a free-living water borne larval stage (cercariae) to adult worms completely adapted to the saline host environment. After penetration through the host's skin, the cercariae transform into schistosomula that become adjusted to the prevailing conditions in the mammalian host. As the schistosomula evolve to the adult stage, the parasites display marked sexual dimorphism, which implies physiological peculiarities associated with gametogenesis and reproduction. To a certain extent, the morphology and physiology of the mature parasites depends on their continuous interaction as a pair. A proportion of the eggs laid by the female worms are excreted from the definitive host and shed into fresh water where they hatch and release free living larvae, the miracidium, that will infect the snail, its intermediary host. In the snail, several generations occur, culminating with the release of cercariae.

ENHANCED EFFICIENCY OF RNA-GUIDED CAS12a VERSUS CAS9 TRANSGENE KNOCK-IN AND ACTIVITY AT ASCHISTOSOMA MANSONIGENOME SAFE HARBOR

“…To this end, Cas9 and Cas12a were each applied together with a 5'C6-PEG10-modified donor template encoding an EGFP reporter-gene under control of the strong native ubiquitin promoter of S. mansoni (21). We analyzed this promoter in more detail and identified several core promoter elements (76,77,(121)(122)(123), including a schistosomal Kozak sequence (78). The promoter elements identified may contribute to the constitutive transcriptional activity of the affiliated ubiquitin gene throughout the schistosome life cycle (79).…”

Enhanced Efficiency of Rna-guided Cas12a Versus Cas9 Transgene Knock-in and Activity at a Schistosoma Mansoni Genome Safe Harbor

“…Cas9 and Cas12a were each introduced into NLE the presence of a 5'C6-PEG10-modified donor template coding for EGFP under control of the endogenous ubiquitin promoter of S. mansoni 21 . We analyzed this promoter in detail and identified several core promoter elements 49,51,[107][108][109] , including a schistosomal Kozak sequence 52 . The promoter elements may contribute to the constitutive transcriptional activity of the cognate ubiquitin gene in the developmental cycle 53 .…”