microPublication biology最新文献

Changes in lipid composition at membrane fusion sites in mating Tetrahymena are thought to involve the endoplasmic reticulum (ER), but its localization to these sites has not been observed. Here we show ER distribution during Tetrahymena mating using TtRET1-GFP and GFP-KDEL. We find that both markers localize to perinuclear membranes and tubular structures that connect perinuclear membrane to plasma membrane at fusion sites. Interestingly, both markers disappear from parental macronuclei after emergence of zygotic macronuclei. These similarities in localization of established ER marker, GFP-KDEL, and TtRET1-GFP reveal TtRET1-GFP as a useful new live cell marker for the ER in Tetrahymena.

The mitochondrial ribosome (mitoribosome) translates mitochondrial genome encoded proteins essential for cellular energy production. Given this critical role, defects in the mitoribosome can cause mitochondrial stress and manifest as multisystemic diseases. In a screen for unique activators of the mitochondrial unfolded protein response (UPR ^mt ) in Caenorhabditis elegans , we recovered a strain harboring a missense mutation in the gene encoding mitochondrial ribosome protein S31 ( MRPS-31 )-a component of the mitoribosome small subunit. Herein, we confirm causality of the mrps-31 allele and characterize its induction of UPR ^mt and impact on organismal development, providing a valuable model for further study of the mitoribosome.

The serine/threonine protein kinase SGK-1 is a downstream target of mTOR complex 2 (mTORC2) and is a conserved regulator of growth and metabolism. In C. elegans , mutations in rict-1 , which encodes an essential component of mTORC2, impairs lipid homeostasis and growth; however, these defects are partially suppressed by an activating mutation in SGK-1 , E116K. Here, we describe a stronger gain-of-function mutation in sgk-1 , L112F, that was identified in a forward genetic screen for rict-1 suppressor mutations . This allele will be useful in further dissecting the mTORC2 pathway and provides new insight into the role of this conserved residue in regulating SGK-1 kinase activity.

Genetic screens in Drosophila melanogaster have long been used to identify genes found in a variety of developmental, cellular, and behavioral processes. Here we describe the characterization and mapping of a mutation identified in a conditional screen for genetic regulators of cell growth and cell division. Within a Flp/FRT system, mutant G.3.2 results in a reduction of mutant tissue and a rough eye phenotype. We find that G.3.2 maps to the gene cnk , providing further support that cnk is a critical gene in Drosophila eye development. This mutant was characterized, mapped and sequenced by undergraduate students within the Fly-CURE consortium.

Sulfoquinovosyldiacylglycerol (SQDG) is a plant sulfolipid that plays a major role in the global sulfur cycle. Bacteria contain sulfoglycolytic pathways that are responsible for metabolizing SQDG which requires initial delipidation by a sulfolipase and sulfoquinovosidase (SQase). Recently, a new group of SQases was discovered and have been categorized in a separate glycoside hydrolase family (GH188). Here we have identified a subset of GH188s with an altered sulfonate binding residue. We found that these GH188s have a distinct dimer interface and are found in unique gene clusters that may represent new sulfoglycolytic pathways. Further investigation into these enzymes could broaden our understanding of this new glycoside hydrolase family and uncover diverse sulfoglycolytic pathways.

C. elegans nematodes possess expanded families of Hedgehog related (Hh-r) and Patched/Dispatched-related (PTR) proteins but their functional relationship remains unclear. Here we investigated whether CHE-14 , the closest C. elegans ortholog for the Hedgehog transporter Dispatched, was necessary for the secretion of two tagged Hh-r proteins: WRT-10 and GRL-2 . We report that CHE-14 is dispensable for the apical localization of GRL-2 and WRT-10 . We also show that animals lacking CHE-14 and another redundant PTR protein DAF-6 also secrete WRT-10 , suggesting neither are required for secretion of these specific Hh-r proteins.

High-throughput imaging enables rapid collection of large datasets and is used widely in many systems. However, this is not often used in plant-based systems due to issues related to the need to mount tissues and autofluorescence of plant metabolites. We therefore developed methodology enabling high-throughput imaging of Arabidopsis roots. In this system, growth media supplemented with India Ink (to block autofluorescence from cotyledons) is poured directly into multi-well coverglass-bottom plates and seedlings grown such that the roots grow down with the gravity vector and along the coverglass, effectively mounting themselves for imaging. This method enables high-throughput imaging of Arabidopsis roots.

Gene model for the ortholog of Phosphatase and tensin homolog ( Pten ) in the D. miranda Apr. 2013 (UC Berkeley DroMir_2.2/DmirGB2) Genome Assembly (GenBank Accession: GCA_000269505.2 ) of Drosophila miranda . This ortholog was characterized as part of a developing dataset to study the evolution of the Insulin/insulin-like growth factor signaling pathway (IIS) across the genus Drosophila using the Genomics Education Partnership gene annotation protocol for Course-based Undergraduate Research Experiences.

Hybrid offspring dysfunction in cytoplasmic-nuclear hybrids (cybrids) implies that one parent's mitochondrial genome is incompatible with the nuclear genome of the other parent. In Caenorhabditis briggsae , cybrids exhibit increased mitochondrial reactive oxygen species (ROS). In this study, we measured the specific activity of markers for mitochondrial abundance (citrate synthase) and antioxidant enzyme response (catalase) in four C. briggsae cybrid lines. An increase of catalase expression but not in mitochondrial abundance was found in dysfunctional cybrids. This suggests that organisms might compensate for some genetic incompatibilities by modulating gene expression of key oxidative stress enzymes such as catalase.

Calcium signaling plays an integral role in neuronal communication and muscle movement. The junctophilin family of proteins are structural components of calcium channels of the endoplasmic reticulum and are implicated in various neurodegenerative disorders. This study examined the function of jph-1 , a gene coding for a junctophilin protein in Caenorhabditis elegans ( C. elegans ), by downregulating jph-1 gene expression using RNAi through bacterial feeding. Downregulation of jph-1 altered the physical morphology and impaired thrashing locomotion in wild-type C. elegans . These results are consistent with those of others in demonstrating a role for jph-1 in muscle physiology.