Institute of Environmental and Agricultural Biology (X-BIO), University of Tyumen, Tyumen, Russia.
Timiryazev Agricultural Academy, Russian State Agrarian University Moscow, Moscow, Russia.
J Exp Zool A Ecol Integr Physiol. 2022 Jul;337(6):675-686. doi: 10.1002/jez.2599. Epub 2022 Apr 22.
The anomaly P is a mass morphological anomaly reported in some water frog populations across Europe. It was found that polydactyly is only a mild attenuated form of heavy cases of the anomaly P syndrome, which have strong deformations of the hindlimbs and, partly, forelimbs. It was shown that the anomaly P is caused by the trematode Strigea robusta and this syndrome can be considered as a special case of strigeosis in amphibians. The anomaly P for a long time considered to be specific for water frogs of the genus Pelophylax. Herein, we describe polydactyly and heavy forms of the anomaly P syndrome in toads of the genera Bufo and Bufotes, as a result of exposure to S. robusta cercariae. A total of 150 tadpoles of Bufo bufo, 60 tadpoles of Bufotes viridis, and 60 tadpoles of Bufotes baturae were divided into five experimental and four control groups (30 tadpoles in each group). All anomalies in the toads were similar to those observed in water frogs. The survival of tadpoles in the experimental groups was 76%. The anomaly P was observed in 57.9% of toad tadpoles (51.8% of mild forms and 6.1% of heavy forms). The occurrence of the anomaly P varied among groups from 19% to 78%. Heavy forms of the anomaly P were found in all experimental groups. We described rare asymmetrical cases of the anomaly P. According to severe modification of limb morphology, we supposed changes of gonadal morphology (any modifications of the germ and somatic cells). The gonadal development of infected tadpoles was however the same as in uninfected toad tadpoles, and heterochromatin distribution within gonocytes had no differences as well. It seems like the parasite doesn't have any effect on the gonadal development of the toads. The lack of heavy forms in natural populations of toads, as well as a development of gonads were discussed.
异常 P 是一种在欧洲部分水蛙种群中报告的形态异常。研究发现，多指只是异常 P 综合征的一种轻度减弱形式，该综合征后腿和部分前腿畸形严重。研究表明，异常 P 是由吸虫 Strigea robusta 引起的，这种综合征可以被认为是两栖动物中 Strigeosis 的一种特殊情况。异常 P 长期以来被认为是 Pelophylax 属水蛙的特有现象。在此，我们描述了蟾蜍属 Bufo 和 Bufotes 的蟾蜍因暴露于 Strigea robusta 尾蚴而出现的多指和异常 P 综合征的严重形式。总共将 150 只蟾蜍 Bufo bufo 幼体、60 只 Bufotes viridis 幼体和 60 只 Bufotes baturae 幼体分为五个实验组和四个对照组（每组 30 只幼体）。蟾蜍所有的异常都与在水蛙中观察到的异常相似。实验组幼体的存活率为 76%。在蟾蜍幼体中观察到异常 P 的发生率为 57.9%（轻度形式为 51.8%，重度形式为 6.1%）。异常 P 的发生率在各组之间从 19%到 78%不等。所有实验组都发现了严重形式的异常 P。我们描述了罕见的异常 P 不对称案例。根据四肢形态的严重改变，我们推测生殖腺形态发生了变化（生殖细胞和体细胞的任何改变）。然而，受感染的幼体的生殖腺发育与未受感染的蟾蜍幼体相同，生殖细胞内异染色质的分布也没有差异。似乎寄生虫对蟾蜍的生殖腺发育没有任何影响。还讨论了自然种群中蟾蜍缺乏严重形式以及生殖腺发育的问题。
