Fig 1.
Study begins at Timepoint 1 with all the cats from group obese (GO) and group lean (GL) with a BCS of ≤ 5.5. Blood glucose measurement and dual X-ray absorptiometry as well as biopsy samples of white adipose and muscle tissue were performed. All cats were fed ad libitum from then on until GO had a BCS of ≥ 6, while GL maintained a BCS of ≤ 5.5. Measurement of blood glucose and dual X-ray absorptiometry as well as biopsies of white adipose and muscle tissue were performed again.
Fig 2.
Linear regression analysis of BCS against the body fat content.
A total of six cats (3 lean, 3 obese) were measured for BCS and body fat content (%) over two timepoints, T1 = before ad libitum feeding; T2 = after ad libitum feeding. n = 12 datapoints. Body condition scoring according to LaFlamme.
Fig 3.
Number of differentially expressed genes in muscle tissue (left) and adipose tissue (right). n = 6 cats (3 cats phenotype lean, 3 cats phenotype obese).
Timepoint 1 (T1), all 6 cats lean due to preliminary energy restricted feeding of the 3 phenotypically obese cats until they reached a BCS of 5.5. Timepoint 2 (T2), cats segregated again into 3 lean and 3 obese individuals, respectively, due to ad libitum feeding. white = upregulated genes of phenotype obese compared to phenotype lean respectively within phenotype itself T2 compared to T1, black = downregulated genes of phenotype obese compared to phenotype lean respectively within phenotype itself T2 compared to T1. Unit = exact number of differentially expressed genes. Differential gene expression analysis based on RNA sequencing, assuming FDR < 0.2 and logFC > 1; FDR = false discovery rate; logFC = Log fold change.
Fig 4.
Cluster Heat Map of adipose tissue samples from cats sampled at two different time points and expressing varying genetic predisposition to obesity. n = 6 cats (3 cats without genetic predisposition to obesity (GL 1, GL 2, GL 3), 3 cats with genetic predisposition to obesity (GO 1, GO 2, GO 3; all cats belonged to European Shorthair cats from an experimental cat colony.
T1 = Timepoint 1 (all cats lean (BCS ≤ 5.5) after energy restricted feeding prior to sampling), T2 = Timepoint 2 (Cats segregated into three lean (BCS ≤ 5.5) and three obese cats (BCS ≥ 6) after ad libitum feeding from T1 on. Genetic predisposition of half of the study cats was induced by crossbreeding.
Fig 5.
Cluster Heat Map of muscle tissue samples from cats sampled at two different time points and expressing varying genetic predisposition to obesity. n = 6 cats (3 cats without genetic predisposition to obesity (leanGL1, GL2, GL3), 3 cats with genetic predisposition to obesity (obese, GO1, GO2, GO3); all cats belonged to European Shorthair cats from an experimental cat colony.
T1 = Timepoint 1 (all cats lean (BCS ≤ 5.5) after energy restricted feeding; T2 = Timepoint 2 (Cats segregated into three lean (BCS ≤ 5.5) and three obese cats (BCS ≥ 6) after ad libitum feeding from T1 on. Genetic predisposition of half of the study cats was induced by crossbreeding. “Contamination” represents an unexpected subcluster which, according to annotation, represents a contamination of adipose tissue with non-adipose tissue. Based on the expression pattern it was concluded the non-adipose tissue to be muscle tissue from T1.
Fig 6.
Gene Ontology Biological Process enrichment analysis (ORA) of differentially expressed genes in adipose tissue, n = 3 cats phenotype lean, comparing Timepoint 1 (T1) and Timepoint 2 (T2).
The dot plot displays the top significantly enriched terms. The x-axis shows the gene ratio (number of DE genes in a term divided by total number of genes in that term). Dot size corresponds to the count of DE genes per term, and color represents adjusted p-values (red = more significant).
Fig 7.
Gene Ontology Biological Process enrichment analysis (ORA) of differentially expressed genes in adipose tissue, n = 6 cats (3 cats phenotype lean (GL), 3 cats phenotype obese (GO)), comparing GO over GL at Timepoint 1 (T1).
The dot plot displays the top significantly enriched terms. The x-axis shows the gene ratio (number of DE genes in a term divided by total number of genes in that term). Dot size corresponds to the count of DE genes per term, and color represents adjusted p-values (red = more significant).
Fig 8.
Gene Ontology Biological Process enrichment analysis (ORA) of differentially expressed genes in adipose tissue, n = 3 cats phenotype obese, comparing Timepoint 1 (T1) and Timepoint 2 (T2).
The dot plot displays the top significantly enriched terms. The x-axis shows the gene ratio (number of DE genes in a term divided by total number of genes in that term). Dot size corresponds to the count of DE genes per term, and color represents adjusted p-values (red = more significant).
Fig 9.
Gene Ontology Biological Process enrichment analysis (ORA) of differentially expressed genes in adipose tissue, n = 6 cats (3 cats phenotype lean (GL), 3 cats phenotype obese (GO)), comparing GO over GL at Timepoint 2 (T2).
The dot plot displays the top significantly enriched terms. The x-axis shows the gene ratio (number of DE genes in a term divided by total number of genes in that term). Dot size corresponds to the count of DE genes per term, and color represents adjusted p-values (red = more significant).