Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree Frogs

The amphibian chytrid fungus, <i>Batrachochytrium dendrobatidis</i> (<i>Bd</i>), has been implicated as an agent of acute declines in amphibian populations worldwide. East Asian amphibians have been coexisting with <i>Bd</i> for long periods and thus are considere...

Full description

Saved in:
Bibliographic Details
Main Authors: Ji-Eun Lee, Jun-Kyu Park, Yuno Do
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Animals
Subjects:
Online Access:https://www.mdpi.com/2076-2615/15/2/154
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832589317287968768
author Ji-Eun Lee
Jun-Kyu Park
Yuno Do
author_facet Ji-Eun Lee
Jun-Kyu Park
Yuno Do
author_sort Ji-Eun Lee
collection DOAJ
description The amphibian chytrid fungus, <i>Batrachochytrium dendrobatidis</i> (<i>Bd</i>), has been implicated as an agent of acute declines in amphibian populations worldwide. East Asian amphibians have been coexisting with <i>Bd</i> for long periods and thus are considered resistant; among the many is the Japanese tree frog, <i>Dryophytes japonicus</i>. Our study focused <i>Bd</i> infection effects on reproductive behaviors and physiological parameters in <i>D. japonicus</i> as a function of better understanding the chronic effect of the disease on long-term population viability. During the peak breeding season, we captured 70 males and quantified the chorus size, calling behaviors, physiological states, innate immunity, and sperm quality of individuals. In a simple comparison, all parameters were not significantly different. However, in the NMDS analysis, we were able to confirm subtle trends in some items according to infection and correlations between several items. Importantly, sperm density and sperm vitality tend to increase with <i>Bd</i> infection load, suggesting increased reproductive effort following infection. Additionally, this analysis indicated that innate immunity was positively related to <i>Bd</i> infection intensities, indicating the activation of immunity upon infection. These findings indicate that <i>Bd</i>-resistant <i>D. japonicus</i> maintains reproductive capabilities and physio-logical stability despite <i>Bd</i> infection, likely due to a co-evolved immune system. The present work offers insight into how amphibian populations may have some endurance in the presence of <i>Bd</i> and points out the importance of studying resistant species as a means to understand long-term ecological effects. Our results suggest that resistance to <i>Bd</i> may not simply prevent cata-strophic declines but actively contribute to the dynamics of <i>Bd</i> prevalence in amphibian communities, and confer implications for conservation strategies.
format Article
id doaj-art-3815cdffdb7d4b42bc3a04b92ba47217
institution Kabale University
issn 2076-2615
language English
publishDate 2025-01-01
publisher MDPI AG
record_format Article
series Animals
spelling doaj-art-3815cdffdb7d4b42bc3a04b92ba472172025-01-24T13:17:47ZengMDPI AGAnimals2076-26152025-01-0115215410.3390/ani15020154Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree FrogsJi-Eun Lee0Jun-Kyu Park1Yuno Do2Department of Biological Sciences, Kongju National University, Gongju 32588, Republic of KoreaDepartment of Biological Sciences, Kongju National University, Gongju 32588, Republic of KoreaDepartment of Biological Sciences, Kongju National University, Gongju 32588, Republic of KoreaThe amphibian chytrid fungus, <i>Batrachochytrium dendrobatidis</i> (<i>Bd</i>), has been implicated as an agent of acute declines in amphibian populations worldwide. East Asian amphibians have been coexisting with <i>Bd</i> for long periods and thus are considered resistant; among the many is the Japanese tree frog, <i>Dryophytes japonicus</i>. Our study focused <i>Bd</i> infection effects on reproductive behaviors and physiological parameters in <i>D. japonicus</i> as a function of better understanding the chronic effect of the disease on long-term population viability. During the peak breeding season, we captured 70 males and quantified the chorus size, calling behaviors, physiological states, innate immunity, and sperm quality of individuals. In a simple comparison, all parameters were not significantly different. However, in the NMDS analysis, we were able to confirm subtle trends in some items according to infection and correlations between several items. Importantly, sperm density and sperm vitality tend to increase with <i>Bd</i> infection load, suggesting increased reproductive effort following infection. Additionally, this analysis indicated that innate immunity was positively related to <i>Bd</i> infection intensities, indicating the activation of immunity upon infection. These findings indicate that <i>Bd</i>-resistant <i>D. japonicus</i> maintains reproductive capabilities and physio-logical stability despite <i>Bd</i> infection, likely due to a co-evolved immune system. The present work offers insight into how amphibian populations may have some endurance in the presence of <i>Bd</i> and points out the importance of studying resistant species as a means to understand long-term ecological effects. Our results suggest that resistance to <i>Bd</i> may not simply prevent cata-strophic declines but actively contribute to the dynamics of <i>Bd</i> prevalence in amphibian communities, and confer implications for conservation strategies.https://www.mdpi.com/2076-2615/15/2/154amphibiandisease sensitivityhost-pathogen interactionpopulation sustainabilityterminal investment
spellingShingle Ji-Eun Lee
Jun-Kyu Park
Yuno Do
Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree Frogs
Animals
amphibian
disease sensitivity
host-pathogen interaction
population sustainability
terminal investment
title Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree Frogs
title_full Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree Frogs
title_fullStr Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree Frogs
title_full_unstemmed Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree Frogs
title_short Analysis of Reproductive Strategies and Immunological Interactions in <i>Batrachochytrium dendrobatidis</i>-Resistant Japanese Tree Frogs
title_sort analysis of reproductive strategies and immunological interactions in i batrachochytrium dendrobatidis i resistant japanese tree frogs
topic amphibian
disease sensitivity
host-pathogen interaction
population sustainability
terminal investment
url https://www.mdpi.com/2076-2615/15/2/154
work_keys_str_mv AT jieunlee analysisofreproductivestrategiesandimmunologicalinteractionsinibatrachochytriumdendrobatidisiresistantjapanesetreefrogs
AT junkyupark analysisofreproductivestrategiesandimmunologicalinteractionsinibatrachochytriumdendrobatidisiresistantjapanesetreefrogs
AT yunodo analysisofreproductivestrategiesandimmunologicalinteractionsinibatrachochytriumdendrobatidisiresistantjapanesetreefrogs