Project description:Developmental transitions involve changes in the genetic programs governing molecular processes. Characterizing these genetic programs gives us insight into how genes work to orchestrate developmental transitions in morphology, physiology, or even behavior. One fascinating developmental transition, metamorphosis, bridges larval and juvenile periods. Southern Flounder, a flatfish, is an ideal model system to investigate these developmental states due to dramatic phenotypic changes during metamorphosis. Here, we use transcriptomics to investigate how genetic programs orchestrate larval development, metamorphosis, and juvenile development in Southern Flounder. Our analysis of Southern Flounder transcriptomes comprehensively describes distinct larval and juvenile genetic programs that overlap during metamorphosis. We also describe a third genetic program that peaks during metamorphosis. These results provide insight into molecular orchestration of flatfish and teleost metamorphosis and more generally into how the timing of genetic programs orchestrates metamorphosis. We also propose that these program trajectories can be used to pinpoint timing of metamorphosis in animals with less phenotypically distinct larval and juvenile forms.
Project description:Shallow-water ascidians are prevalent invasive and fouling organisms within marine ecosystems. Their larvae undergo rapid metamorphosis from planktonic to sessile stage, facilitating colonization and population expansion. It is crucial to explore the molecular and cellular orchestration of larval metamorphosis in order to gain a deep understanding of ascidian environmental adaptability, as well as to develop effective methods for bioinvasion and biofouling control. Here, we conducted 4D-label free quantitative proteomics combined with transcriptomics to monitor protein and gene expression across five distinct developmental stages from swimming larva to metamorphic juvenile of ascidian Ciona. We identified a total of 6,043 proteins, approximately 83.6% of which were quantified. We delineated the temporal dynamics of protein expression during ascidian metamorphosis and identified differentially expressed proteins between stages.
Project description:Drosophila melanogaster undergoes a complete metamorphosis, during which time the larval male and female forms transition into sexually dimorphic, reproductive adult forms. To understand this complex morphogenetic process at a molecular-genetic level, we performed whole genome microarray analyses. Genes were identified that were expressed during metamorphosis in both somatic and germline tissues of males and females. Additionally, genes were identified that display sex-specific differences in abundance in both of these tissues at discrete times during metamorphosis. Keywords: time course; wild type; genetic modification;
Project description:Drosophila melanogaster undergoes a complete metamorphosis, during which time the larval male and female forms transition into sexually dimorphic, reproductive adult forms. To understand this complex morphogenetic process at a molecular-genetic level, we performed whole genome microarray analyses. Genes were identified that were expressed during metamorphosis in both somatic and germline tissues of males and females. Additionally, genes were identified that display sex-specific differences in abundance in both of these tissues at discrete times during metamorphosis. Keywords: time course; wild type; genetic modification; Gene expression was examined at five time points during metamorphosis: 0, 24, 48, 71, and 96 hr After Puparium Formation (APF). Gene expression was examined separately in males and females for both wild type pupae and tudor (tud) progeny. tud progeny have genetically ablated germline tissues. All samples were labeled with Cy5 and compared against a common reference sample labeled with Cy3. The reference sample contained male and female wild type pupae from all stages of metamorphosis. All experiments were conducted in triplicate.
Project description:Tunicates, including ascidians, are recognized as the true “sister group” of vertebrates and are emerging as models to study the development and degeneration of central nervous system (CNS). Ascidian larvae have the typical chordate body plan that includes a dorsal neural tube. During their metamorphosis, a deep tissue reorganization takes place, with some tissues that degenerate while others develop to become functional during the adult life. The larval CNS also degenerates and most neurons disappear, making room to the formation of adult CNS. The genome of the ascidian Ciona intestinalis has been sequenced and annotated, with several CNS specific genes that have been characterized, revealing specification mechanisms shared with humans. These features make ascidian metamorphosis a good model to study the mechanisms underlying physiological CNS degeneration and to compare them to the pathological condition typical of neurodegenerative diseases. In order to shed light on the molecular determinants of C. intestinalis metamorphosis and neurodegeneration, we analyzed its transcriptome at three stages of development: swimming larva (SwL, Hotta stage 28), settled larva (SetL, Hotta stage 32) and metamorphosing larva (MetL, Hotta stage 34). Supported by SoE-SEED-2020 Grant, University of Milan.
Project description:The veined rapa whelk (Rapana venosa) is widely consumed in China but is also a predator that is reducing bivalves resources in oceans worldwide. Larval metamorphosis of this species, a pelagic to benthic transition that involves considerable structural and physiological changes, plays a pivotal role in its commercial breeding and natural populations. Thus, the endogenous microRNA that drive this transition attract considerable interest. This study is the first to investigate alterations of miRNA expression during metamorphosis in a marine gastropod by using high-throughput sequencing. A total of 195 differentially expressed miRNAs were obtained, including 65 miRNAs differentially expressed during the transition from pre-competent larva to competent larva (33 up-regulated and 32 down regulated) and 123 miRNAs differentially expressed during competent to post larva transition (96 up-regulated and 27 down regulated). Our data improve understanding of the microRNA function into R. venosa metamorphosis and provide a solid basis for further study.
Project description:Bacteria assume distinct lifestyles during the planktonic and biofilm modes of growth. In biofilms, they are more tolerant to antibiotics and can evade the immune system response more effectively. However, little is known regarding the molecular determinants involved in biofilm formation by Gardnerella vaginali, the predominant species found in bacterial vaginosis (BV). Hence, to gain insight into the pathogenesis of G. vaginalis, we carried out a comparative transcriptomic analysis between planktonic and biofilm phenotypes, using RNA-sequencing. The major alterations observed were related with the transcription of genes involved in cell wall biogenesis and typical stress factors, in which was found significantly up-regulated in biofilms, resulting in a protected mode of bacterial growth. In addition, biofilm phenotype was characterized by low metabolic activity, which is appropriate to guarantee long term survival during BV recurrence.
Project description:Many known miRNAs in fish come from zebrafish and fugu whose genome sequence data are available. The Japanese flounder undergoes typical metamorphosis which is characterized by major morphological, functional, and behavioral changes during growth due to this metamorphosis from larva to juvenile. Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Here, the high-throughput sequencing was adopted to identify the miRNAs during metamorphosis in the Japanese flounder. We found abundant microRNAs during metamorphosis in the Japanese flounder. Small RNAs were sequenced from metamorphosis stages of Japanese flounder
Project description:Many known miRNAs in fish come from zebrafish and fugu whose genome sequence data are available. The Japanese flounder undergoes typical metamorphosis which is characterized by major morphological, functional, and behavioral changes during growth due to this metamorphosis from larva to juvenile. Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Here, the high-throughput sequencing was adopted to identify the miRNAs during metamorphosis in the Japanese flounder. We found abundant microRNAs during metamorphosis in the Japanese flounder.
Project description:Why is metamorphosis so pervasive? Does it facilitate the independent (micro)evolution of quantitative traits in distinct life-stages, like it does for discrete characters such as limbs and organs? We tested this hypothesis by measuring the expression of 6400 genes in 41 Drosophila melanogaster inbred lines at larval and adult stages. Only 32% of the genes showed significant genetic correlations between larval and adult expression. By contrast, 44% of the traits showed some level of independence between stages. Gene ontology terms enrichment of the functions most and least constrained among stages revealed that traits related to immunity emerged as largely correlated between larvae and adults. Direct comparisons with other datasets showed that inter-stage constraints were lower than inter-sexual or cross-environment genetic constraints. These results show that metamorphosis enables a large part of the transcriptome to evolve independently at different life-stages and identify biological functions under high and low genetic constraints.