TY - JOUR
T1 - Sexual conflict in action: An antagonistic relationship between maternal and paternal sex allocation in the tammar wallaby, Notamacropus eugenii
AU - Edwards, Amy M
AU - Cameron, Elissa Z
AU - DEAKIN, Janine
AU - EZAZ, Tariq
AU - Pereira, Jorge E
AU - Ferguson-Smith, Malcolm
AU - Robert, Kylie A.
PY - 2019/4/5
Y1 - 2019/4/5
N2 - Sex ratio biases are often inconsistent, both among and within species and populations. While some of these inconsistencies may be due to experimental design, much of the variation remains inexplicable. Recent research suggests that an exclusive focus on mothers may account for some of the inconsistency, with an increasing number of studies showing variation in sperm sex ratios and seminal fluids. Using fluorescent in‐situ hybridization, we show a significant population‐level Y‐chromosome bias in the spermatozoa of wild tammar wallabies, but with significant intraindividual variation between males. We also show a population‐level birth sex ratio trend in the same direction toward male offspring, but a weaning sex ratio that is significantly female‐biased, indicating that males are disproportionately lost during lactation. We hypothesize that sexual conflict between parents may cause mothers to adjust offspring sex ratios after birth, through abandonment of male pouch young and reactivation of diapaused embryos. Further research is required in a captive, controlled setting to understand what is driving and mechanistically controlling sperm sex ratio and offspring sex ratio biases and to understand the sexually antagonistic relationship between mothers and fathers over offspring sex. These results extend beyond sex allocation, as they question studies of population processes that assume equal input of sex chromosomes from fathers, and will also assist with future reproduction studies for management and conservation of marsupials.
AB - Sex ratio biases are often inconsistent, both among and within species and populations. While some of these inconsistencies may be due to experimental design, much of the variation remains inexplicable. Recent research suggests that an exclusive focus on mothers may account for some of the inconsistency, with an increasing number of studies showing variation in sperm sex ratios and seminal fluids. Using fluorescent in‐situ hybridization, we show a significant population‐level Y‐chromosome bias in the spermatozoa of wild tammar wallabies, but with significant intraindividual variation between males. We also show a population‐level birth sex ratio trend in the same direction toward male offspring, but a weaning sex ratio that is significantly female‐biased, indicating that males are disproportionately lost during lactation. We hypothesize that sexual conflict between parents may cause mothers to adjust offspring sex ratios after birth, through abandonment of male pouch young and reactivation of diapaused embryos. Further research is required in a captive, controlled setting to understand what is driving and mechanistically controlling sperm sex ratio and offspring sex ratio biases and to understand the sexually antagonistic relationship between mothers and fathers over offspring sex. These results extend beyond sex allocation, as they question studies of population processes that assume equal input of sex chromosomes from fathers, and will also assist with future reproduction studies for management and conservation of marsupials.
KW - Macropus eugenii
KW - maternal
KW - offspring sex ratio
KW - paternal
KW - sperm sex ratio
UR - http://www.scopus.com/inward/record.url?scp=85064840936&partnerID=8YFLogxK
UR - https://onlinelibrary.wiley.com/doi/abs/10.1002/ece3.4813?af=R
UR - http://www.mendeley.com/research/sexual-conflict-action-antagonistic-relationship-between-maternal-paternal-sex-allocation-tammar-wal
U2 - 10.1002/ece3.4813
DO - 10.1002/ece3.4813
M3 - Article
SN - 2045-7758
VL - 9
SP - 4340
EP - 4348
JO - Ecology and Evolution
JF - Ecology and Evolution
IS - 8
ER -