Cycles of antler and testicular growth in an aseasonal tropical deer (Axis axis)

Abstract

Summary. Antler

Neel revisited: the adipocyte, seasonality and type 2 diabetes

“…In addition, shift work is associated with an increased risk of cardiovascular disease [46,47], reported in one study as conveying a 1.6-and 3.0-fold increased risk for men and women, respectively, in the 45-55 year age group [46,48]. As noted earlier in this article, it is particularly interesting to note that, in some mammals, migration north is accompanied by a chronic retention of circannual photoperiodicity appropriate for the region from which the animal is derived, rather than that in which it has settled [36]. This maladapted cycle can be transmitted through subsequent generations, even when the original animal and its offspring remain in the northern hemisphere [34,36].…”

“…As noted earlier in this article, it is particularly interesting to note that, in some mammals, migration north is accompanied by a chronic retention of circannual photoperiodicity appropriate for the region from which the animal is derived, rather than that in which it has settled [36]. This maladapted cycle can be transmitted through subsequent generations, even when the original animal and its offspring remain in the northern hemisphere [34,36]. It Fig.…”

“…A second equally astonishing finding is that there appear to be two clock pathways, one involving the pineal gland, which regulates short photoperiodicity, and a second involving pituitary calendar cells, which has much longer term effects [34]. The latter process seems to be more embedded in longer living animals, and there is evidence that this cycle survives migration from the tropics to the northern hemisphere and even through subsequent generations [36].…”

Seasonal changes of testicular parameters in southern pudu Pudu puda in relationship to circannual variation of its reproductive hormones

“…Such extended period of male fertility was reported not only in the tropical Eld's deer (Monfort et al 1993) and Reeve's muntjac (Chapman and Harris 1991), temperate axis deer (Loudon and Curlewis 1988) and the atypically breeding cervids such as the roe deer (Stieve 1949), but was also observed in the typically short-day breeding cervids, such as the red deer (Lincoln 1971, Bubenik et al 1985, wapiti (Haigh et al 1984), white-tailed deer (Mirarchi et al 1977), and sika deer (Suzuki et al 1992).…”

“…Circannual changes of reproductive hormones were also investigated in males of subtropical and tropical deer, such as Rusa deer Cervus rusa timorensis (van Mourik and Stelmasiak 1990), axis deer Axis axis (Loudon andCurlewis 1988, Bubenik et al 1991), muntjac Muntiacus reevesi (Chapman and Harris 1991) and Eld's deer Cervus eldi thamin (Monfort et al 1993). Most recently, our group determined the rate of development of reproductive organs and circannual variation of luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T), and prolactin (PRL) in plasma of male southern pudu Pudu puda Molina, 1782, a small subtropical deer living in Chile (Reyes et al 1988, Reyes-Toledo et al 1993, Bubenik et al 1996.…”