Expression pattern of cobll1a. (A–H) Spatio-temporal expression profile of the cobll1a gene detected by in situ hybridization in embryos. (A–C)cobll1a is expressed at the one to eight cell stages. (D)cobll1a is ubiquitously expressed at 12 hpf. (E)cobll1a is expressed in the head. (F, G)cobll1a was expressed in the notochord at 24 hpf and 36 hpf. (H)cobll1a is expressed in the eye, brain, liver and digestive system in 72 hpf embryos. (I) Using 18S as the reference gene, RT-qPCR results demonstrated the relative expression of the cobll1a at different stages.

Loss of cobll1a results in a microcephalic phenotype. (A)cobll1a^−/− larvae developed normally at 5 dpf. (B) Transcriptional expression level of cobll1a in cobll1a^−/− embryos at 52 hpf were scrutinized by RT-qPCR, compared with the control. (C) An RNA probe of cobll1a was utilized in situ hybridization of WT and cobll1a^−/− embryos at 24 hpf. (D)cobll1a^−/− juveniles exhibited an enlarged abdomen and smaller eyes and head at 8 months. (E) Genotyping results of cobll1a^−/− as shown in Figure 2A.

Depicts the abnormal liver development observed in the absence of cobll1a. (A) An RNA probe of fabp10a was utilized in situ hybridization of WT and cobll1a^−/− embryos at 4 dpf. (B–D) WT and cobll1a^−/− embryos at 4 dpf were detected with anti-sense RNA probes: intestinal marker fabp2(B), endocrine pancreatic marker insulin(C), and excretory pancreatic marker trypsin(D) through WISH. (E) The mRNA expression level of hepatopancreatic-intestinal development-related genes in WT and cobll1a^−/− embryos were analyzed using RT-qPCR at the 52 hpf stage.

The DEGs analysis of WT and cobll1a^−/− zebrafish embryo transcriptomes. (A) PCA cluster analysis of WT and cobll1a mutant zebrafish embryos demonstrated a significant correlation among three biological replicates in both the WT and cobll1a mutant groups. (B) Clustering heat maps of WT and cobll1a^−/− were divided into two distinct groups. (C) The total number of differential genes in WT and cobll1a mutant zebrafish embryo samples was represented, with red denoting 409 up-regulated genes and blue indicating 423 down-regulated genes. (D) The volcano map displays DEGs between the two groups, with red representing up-regulated genes, blue signifying down-regulated genes, and gray denoting non-DEGs. Each dot represents a gene. (E) KEGG analysis of down-regulated DEGs revealed a significantly enriched pathway. (F) GO enrichment analysis of DEGs provides a description of their functions. Purple indicates up-regulated genes, blue represents down-regulated genes, and red fonts depict corrected p-values. Black font is used for the GO feature comment.

Loss of cobll1a leads to abnormal RA metabolism in zebrafish. (A) Line chart of GSEA results with the right ordinate representing the enrichment score. (B) Cluster heat maps of RA metabolism-related genes in DEGs, displaying significant differences between WT and cobll1a mutant. (C) RT-qPCR analysis of the transcriptional expression level of RA metabolism-related genes at 52 hpf cobll1a^−/− compared with WT. (D, F) The expression of aldh1a2 was decreased in cobll1a^−/−embryos, observed in eye and somatic cells at 24 hpf, in liver and intestinal tissues at four dpf. (E) At 4 dpf, the expression of rdh10 was decreased in cobll1a^−/− embryos. (G) At 4 dpf, the expression of cyp26a1 was increased in cobll1a^−/− embryos. (H) At 4dpf, the expression of rbp4 was decreased in cobll1a^−/− embryos.

Loss of Cobll1a resulted in Abnormal Lipid Metabolism in Zebrafish. (A) Clustering heat maps of lipid anabolism-related genes in DEGs. WT and cobll1a mutated zebrafish embryo samples form two distinct groups. (B) RT-qPCR used to assess transcriptional expression level of lipid anabolism-related genes in cobll1a^−/− embryos at 52 hpf, compared with WT. (C) RT-qPCR analysis of transcriptional expression level of lipid catabolism-related genes in cobll1a^−/− embryos at 52 hpf, compared to the control. (D) At 4 dpf, fasn is expressed in adipocytes and the expression of fasn is up-regulated in cobll1a^−/− embryos. (E) At 5 dpf, Oil Red O staining was used to assess the lipid distribution and content of WT and cobll1a^−/− embryos.

Zebrafish embryos exhibit abnormal lipoprotein metabolism in cobll1a mutant. (A–C) Enrichment analysis of GO molecular function (MF), biological process (BP), and cell component (CC) of biological processes in cobll1a^−/− embryos. (D) Cluster heat maps of genes associated with lipoprotein metabolism, where samples from WT and cobll1a mutant zebrafish embryos are segregated into two distinct groups. (E) Transcriptional expression level of apolipoprotein metabolism-related genes in 52 hpf cobll1a^−/− embryos were analyzed by RT-qPCR compared with WT.