Diversity in reproductive seasonality in the three-spined stickleback,Gasterosteus aculeatus

Abstract

The annual timing of reproduction is a key life history trait with a large effect on fitness. Populations often vary in the timing and duration of reproduction to adapt to different seasonality of ecological and environmental variables between habitats. However, little is known about the molecular genetic mechanisms underlying interpopulation variation in reproductive seasonality. Here, we demonstrate that the three-spined stickleback (Gasterosteus aculeatus) is a good model for molecular genetic analysis of variations in reproductive seasonality. We first compiled data on reproductive seasons of diverse ecotypes, covering marine-anadromous, lake and stream ecotypes, of three-spined stickleback inhabiting a wide range of latitudes. Our analysis showed that both ecotype and latitude significantly contribute to variation in reproductive seasons. Stream ecotypes tend to start breeding earlier and end later than other ecotypes. Populations from lower latitudes tend to start breeding earlier than those from higher latitudes in all three ecotypes. Additionally, stream ecotypes tend to have extended breeding seasons at lower latitudes than at higher latitudes, leading to nearly year-round reproduction in the most southern stream populations. A review of recent progress in our understanding of the physiological mechanisms underlying seasonal reproduction in the three-spined stickleback indicates that photoperiod is an important external cue that stimulates and/or suppresses reproduction in this species. Taking advantage of genomic tools available for this species, the three-spined stickleback will be a good model to investigate what kinds of genes and mutations underlie variations in the physiological signalling pathways that regulate reproduction in response to photoperiod.

Reproductive characteristics, egg and larval development of short ninespine stickleback, Pungitius kaibarae

“…Moreover, the different latitudes of their habitats or different populations may also be a factor for prolonged spawning of the fish. The diversity in spawning period among different populations of the threespine stickleback Gasterosteus aculeatus (G. aculeatus) and the ninespine stickleback Pungitius pungitius (P. pungitius) has been previously reported (Heins et al, 2003;Ishikawa & Kitano, 2020). In this regard, future studies on the reproductive cycle of P. kaibarae in various habitats could provide more detailed information.…”

Environment‐induced changes in reproductive strategies and their transgenerational effects in the three‐spined stickleback

“…Our results show that the experimental manipulation of reproductive photoperiod did not alter the onset of spawning, but the late females laid smaller clutches than the early females during the early season. In sticklebacks, vitellogenesis, the deposition of yolk into oocytes, is stimulated by changes in photoperiod just before the beginning of the spawning season (Baggerman, 1980; Ishikawa & Kitano, 2020). Because the late females matured at the same time as the early females but started receiving a long‐day photoperiod later in the season, they probably had less time to accumulate enough energetic resources for egg production in the early breeding season (Elkin & Reid, 2005; Garrido et al., 2007; Glazier, 1999).…”

“…For this, we carried out an experimental study on the three‐spined stickleback ( Gasterosteus aculeatus ) at the southern edge of its European range, where it reproduces repeatedly throughout a single relatively long breeding season. The three‐spined stickleback shows a marked variation in reproductive seasonality (Ishikawa & Kitano, 2020) and usually mature under a long‐day photoperiod (Borg et al., 2004; Noreikiene et al., 2017). Photoperiod acts as a cue that predicts the forthcoming of favorable conditions (e.g., the maximal food abundance) for breeding sticklebacks.…”

Minimally invasive brain injections for viral-mediated transgenesis: New tools for behavioral genetics in sticklebacks

“…This makes stickleback uniquely suited system to address the relationship of physiological ecology, anatomy, and social behavior [48]. Other possible physiological signaling pathways amendable to genome editing in sticklebacks have also been proposed [13,[98][99][100][101].…”