Back

The number of anal fin-rays is decided by two heritable traits, anteroposterior length of the anal fin and interval between the anal fin-rays.

Kimura, T.

2025-12-10 developmental biology
10.64898/2025.12.08.692906 bioRxiv
Show abstract

The number of median fin-rays is a readily quantifiable trait that has been previously studied due to its interspecific variation. I observed in F2 progeny from two inbred lines of medaka with differing anal fin-ray numbers (Kaga and Hd-rRII1) that individuals exhibited the same ray number but differed in the anteroposterior length of the anal fin and the interval between the anal fin-rays. Inducing vertebral fusion to shorten the anal fin anteroposterior length resulted in a decrease in ray number. Given reports of an increased ray number during low-temperature development, I reared Hd-rRII1 fry at 17{degrees}C post-hatching, which resulted in an increase in the number of rays. At this temperature, the anal fin anteroposterior length and the interval between the anal fin-rays were also slightly reduced. Since the posterior boundary of the anal fin is determined by Hox genes, I hypothesize that a temperature-sensitive signaling pathway exists downstream of these genes. Collectively, our results suggest that the medaka anal fin-ray number is determined by at least two genetic traits: the anal fin anteroposterior length and the interval between the anal fin-rays.

Matching journals

The top 5 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.