Sex is pivotal for reproduction, healthcare and evolution. In the fish medaka, the Y-chromosomal dmy (also dmrt1bY) serves the sex determiner, which activates dmrt1 for male sex maintenance. However, ...how dmy makes the male decision via initiating testicular differentiation has remained unknown. Here we report that autosomal gsdf serves a male sex initiator. Gene addition and deletion revealed that gsdf was necessary and sufficient for maleness via initiating testicular differentiation. We show that gsdf transcription is activated directly by dmy. These results establish the autosomal gsdf as the first male sex initiator. We propose that dmy determines maleness through activating gsdf and dmrt1 without its own participation in developmental processes of sex initiation and maintenance. gsdf may easily become a sex determiner or other autosomal genes can be recruited as new sex determiners to initiate gsdf expression. Our findings offer new insights into molecular mechanisms underlying sex development and evolution of sex-controlling genes in vertebrates.
•Oloct4 RNA was detectable in the central nervous system (CNS) and tail bud as well as in primordial germ cells in developing embryos.•Oloct4 dosages affected gastrulation, CNS development and ...angiogenesis.•Oloct4 depletion affected neural stem cells development.
Gene oct4 (also called oct3/4 or pou5f1) encodes an octamer-binding transcription factor and is best known for its pluripotency-specific expression and pluripotency-maintaining role in early embryos and embryonic stem cells of mouse and human. Its fish paralog oct4 (also called pou2 or pou5f3) plays divergent roles in embryos and stem cells development. Here the expression and function of the medaka oct4 (Oloct4) during gastrulation and organogenesis were analysed. Oloct4 RNA was abundant in pluripotent cells and differentiated extraembryonic cells of blastula embryos. It was also detectable in primordial germ cells, brain, eye and tail bud at advanced stages. Importantly, oct4 depletion at high dosages severely affected gastrulation and axis formation. Surprisingly, Oloct4 depletion at low dosages also led to embryos that either had defective brain, eye and/or blood vessels or completely lacked them. Oloct4 depletion in transgenic embryos caused the loss of rx2-positive retinal stem cells in the developing eye. Therefore, Oloct4 is essential for gastrulation, central nervous system development as well as angiogenesis in medaka besides its role in pluripotency maintenance. These results together with previous studies suggest that Oloct4 play pleiotropic roles and represent the ancestral prototype of vertebrate oct4 and pou2 genes.
is the primary foodborne pathogen known to cause gastrointestinal infections in humans. Nevertheless, the molecular mechanisms of
pathogenicity are not fully understood. Prophages carry virulence and ...antibiotic resistance genes commonly found in
populations, and they facilitate the spread of virulence and the emergence of pathogenic
strains. In this study, we characterized three such genes,
,
, and
, within the largest prophage gene cluster in
CHN25. The deletion mutants Δ
, Δ
, Δ
, and Δ
were derived with homologous recombination, and the complementary mutants Δ
-com, Δ
-com, Δ
-com, Δ
-com were also constructed. In the absence of the
,
,
, and
genes, the mutants showed significant reductions in low-temperature survivability and biofilm formation (
< 0.001). The Δ
, Δ
, and Δ
mutants were also significantly defective in swimming motility (
< 0.001). In the Caco-2 model, the above four mutants attenuated the cytotoxic effects of
CHN25 on human intestinal epithelial cells (
< 0.01), especially the Δ
and Δ
mutants. Transcriptomic analysis showed that 15, 14, 8, and 11 metabolic pathways were changed in the Δ
, Δ
, Δ
, and Δ
mutants, respectively. We labeled the
gene with superfolder green fluorescent protein (sfGFP) and found it localized at both poles of the bacteria cell. In addition, we analyzed the evolutionary origins of the above genes. In summary, the prophage genes
,
, and
enhance
CHN25's survival in the environment and host. Our work improves the comprehension of the synergy between prophage-associated genes and the evolutionary process of
.
To investigate the impact of the effect of high temperature stimulation on
larvae after a certain period of time, five experimental groups were established at different temperatures. Then, the
under ...high temperature stress was fed at 30°C for 70 days. After that, the growth index of the
was counted and analyzed. In terms of growth index, high temperature stress had significant effects on FCR, FBW, WGR, and SGR of
(
0.05). The SR increased after being stimulated by temperature (
0.1). The study revealed that liver cells of
were harmed by elevated temperatures of 36°C and 38°C. In the experimental group, the activities of digestive enzymes changed in the same trend, reaching the highest point in the 32°C group and then decreasing, and the AMS activity in the 38°C group was significantly different from that in the 30°C group (
< 0.05). The activities of antioxidase in liver reached the highest at 34°C, which was significantly different from those at 30°C (
< 0.05). In addition, the expression levels of
,
,
, and other genes increased in the experimental group, reaching the highest point at 34°C, and the expression level of the
gene reached the highest point at 32°C, which was significantly different from that at 30°C (
< 0.05). However, the expression level of the
gene decreased in the experimental group and reached its lowest point at 34°C (
< 0.05). The expression level of the
gene increased with the highest temperature stimulus and reached its highest point at 38°C (
< 0.05). In the α diversity index of intestinal microorganisms in the experimental group, the observed species, Shannon, and Chao1 indexes in the 34°C group were the highest (
< 0.05), and β diversity analysis revealed that the intestinal microbial community in the experimental group was separated after high temperature stimulation. At the phylum level, the three dominant flora are
,
, and
.
and
abundance increased at the genus level, but
and
abundance decreased. To sum up, appropriate high-temperature stress can enhance the immunity and adaptability of
. These results show that the high temperature stimulation of 32°C-34°C is beneficial to the industrial culture of
.
Crucian carp (
Carassius auratus
) is one of the major freshwater species and is also a common food fish in China. Recently,
Carassius auratus
herpesvirus (CaHV) could induce fatal viral disease with ...high mortality of crucian carp, which had caused huge economic losses. In this study, we described a rapid and simple recombinase-aid amplification (RAA) assay coupled with lateral flow dipstick (LFD), which could achieve sensitive diagnosis of tumor necrosis factor receptor (TNFR) of CaHV within 35 min at 40°C. Our RAA-LFD method had a satisfactory detection limit of 100 gene copies per reaction, which was 100-fold more sensitive than traditional PCR. In addition, no cross-reaction was observed with other viral pathogens, including koi herpesvirus (KHV), cyprinid herpesvirus 2 (CyHV-2), infectious hematopoietic necrosis virus (IHNV), spring viremia of carp virus (SVCV) and grass carp reovirus (GCRV). Furthermore, the overall cost of the method was cut in half compared to previous studies. In conclusion, RAA-LFD assay is therefore, a promising alternative for point-of-care testing (POCT) of CaHV, which is feasible and of certain value in application of aquatic disease control.
Rice is one of the staple foods for the majority of the global population that depends directly or indirectly on it. The yield of this important crop is constantly challenged by various biotic ...stresses. Rice blast, caused by
(
), is a devastating rice disease causing severe yield losses annually and threatening rice production globally. The development of a resistant variety is one of the most effective and economical approaches to control rice blast. Researchers in the past few decades have witnessed the characterization of several qualitative resistance (
) and quantitative resistance (
) genes to blast disease as well as several avirulence (
) genes from the pathogen. These provide great help for either breeders to develop a resistant variety or pathologists to monitor the dynamics of pathogenic isolates, and ultimately to control the disease. Here, we summarize the current status of the isolation of
,
and
genes in the rice-
interaction system, and review the progresses and problems of these genes utilized in practice for reducing rice blast disease. Research perspectives towards better managing blast disease by developing a broad-spectrum and durable blast resistance variety and new fungicides are also discussed.
Goldfish is an ornamental fish with diverse phenotypes. However, the limited genomic resources of goldfish hamper our understanding of the genetic basis for its phenotypic diversity. To provide ...enriched genomic resources and infer possible mechanisms underlying skin pigmentation, we performed a large-scale transcriptomic sequencing on 13 adult goldfish tissues, larvae at one- and three-days post hatch, and skin tissues with four different color pigmentation. A total of 25.52 Gb and 149.80 Gb clean data were obtained using the PacBio and Illumina platforms, respectively. Onto the goldfish reference genome, we mapped 137,674 non-redundant transcripts, of which 5.54% was known isoforms and 78.53% was novel isoforms of the reference genes, and the remaining 21,926 isoforms are novel isoforms of additional new genes. Both skin-specific and color-specific transcriptomic analyses showed that several significantly enriched genes were known to be involved in melanogenesis, tyrosine metabolism, PPAR signaling pathway, folate biosynthesis metabolism and so on. Thirteen differentially expressed genes across different color skins were associated with melanogenesis and pteridine synthesis including mitf, ednrb, mc1r, tyr, mlph and gch1, and xanthophore differentiation such as pax7, slc2a11 and slc2a15. These transcriptomic data revealed pathways involved in goldfish pigmentation and improved the gene annotation of the reference genome.
Nanoplastic (NP) has become a global environmental concern due to its potentially wide distribution and unknown impacts on organisms. Many laboratory studies have reported the short-term toxicity of ...NPs but their long-term effects are unclear. Here, the chronic hepatoxic effects of NPs (diameter 100 nm; 0, 10, and 104 items/L) in medaka (Oryzias latipes) were evaluated after three-month exposure by investigating the alterations in enzymatic biomarkers (digestion, oxidative status, and immunity) and histopathology in the liver. The trypsin and chymotrypsin activities of digestive enzymes were induced at a low concentration of NPs (10 items/L) but inhibited at high concentration (104 items/L); only the amylase activity was significantly decreased in all NP-treated medaka. Oxidative stress was also induced by NP exposure, which was indicated by the responsive superoxide dismutase and catalase. Lysozyme was significantly reduced after exposure to a high concentration of NPs, while alkaline phosphatase was significantly induced at a low concentration. Exposure to NPs also caused liver damage (e.g., congestion and dilated sinusoids). Taken together, our findings show that chronic exposure to NPs at low particle concentrations can impair the liver health of medaka by affecting liver enzymatic functions and causing histological damage. This implies potentially long-term threats of NPs to aquatic organisms, which call for more long-term aquatic toxicological studies on various species using low environmental concentrations.
Rice blast, caused by the
fungus, is one of the most devastating rice diseases worldwide. Developing resistant varieties by pyramiding different blast resistance (
) genes is an effective approach to ...control the disease. However, due to complex interactions among
genes and crop genetic backgrounds, different
-gene combinations may have varying effects on resistance. Here, we report the identification of two core
-gene combinations that will benefit the improvement of
(
) rice blast resistance. We first evaluated 68
rice cultivars at seedling stage by challenging with 58
isolates. To evaluate panicle blast resistance, we inoculated 190
rice cultivars at boosting stage with five groups of mixed conidial suspensions (MCSs), with each containing 5-6 isolates. More than 60% cultivars displayed moderate or lower levels of susceptibility to panicle blast against the five MCSs. Most cultivars contained two to six
genes detected by the functional markers corresponding to 18 known
genes. Through multinomial logistics regression analysis, we found that
,
,
, and
loci contributed significantly to seedling blast resistance, and
,
,
, and
contributed significantly to panicle blast resistance. For gene combinations,
+
and
+
yielded more stable pyramiding effects on panicle blast resistance against all five MCSs and were designated as core
-gene combinations. Up to 51.6%
cultivars in the Jiangsu area contained
, but less than 30% harbored either
or
, leading to less cultivars containing
+
(15.8%) or
+
(5.8%). Only a few varieties simultaneously contained
and
, implying the opportunity to use hybrid breeding procedures to efficiently generate varieties with either
+
or
+
. This study provides valuable information for breeders to develop
rice cultivars with high resistance to blast, especially panicle blast.
Macrobrachium rosenbergii (M. rosenbergii)
, as a species of common prawn, is a delicacy that is consumed all over the world. By interacting with the target gene 3′-untranslated region (3'-UTR), ...microRNAs (miRNAs) regulate its expression and ultimately participate in the regulation of reproductive development. However, research focusing on miRNA regulation during gonadal development in
M. rosenbergii
received very little attention. To explore the association between miRNA and reproduction, we performed RNA sequencing (RNA-seq) on brain and gonad organs in male and female
M. rosenbergii
. A total of 494 miRNAs were obtained in RNA-seq, including 31 and 59 differentially expressed (DE) miRNAs in the brain and gonads, respectively. Furthermore, 9 DE miRNAs were randomly selected from the brain and gonads, and qRT-PCR was conducted to validate the results of RNA-seq. Interestingly, dpu-miR-133 was found to be substantially expressed in the male brain and testis but poorly expressed in the female brain, ovary, and other organs. Analysis of dpu-miR-133 by Targetscan and MiRanda predicted to target
5-HT1
. Furthermore, the dual-luciferase reporter assay manifested that dpu-miR-133 can combine with
5-HT1
. Overall, our research work provides basic data for further study on the miRNA-mediated regulation of brain, gonad, and reproductive development of study
M. rosenbergii
.
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