Detecting Sex-Related Changes to the Metabolome of a Critically Endangered Freshwater Crayfish During the Mating Season

Emily D Lette; Quinton F Burnham; Nathan Lawler; Pierre Horwitz; Mary C Boyce; David I Broadhurst; Rodney Duffy; Annette Koenders

doi:10.3389/fmolb.2021.650839

Detecting Sex-Related Changes to the Metabolome of a Critically Endangered Freshwater Crayfish During the Mating Season

Front Mol Biosci. 2021 Apr 16:8:650839. doi: 10.3389/fmolb.2021.650839. eCollection 2021.

Authors

Emily D Lette¹, Quinton F Burnham¹, Nathan Lawler², Pierre Horwitz¹, Mary C Boyce^{1

2}, David I Broadhurst^{1

2}, Rodney Duffy³, Annette Koenders¹

Affiliations

¹ Centre for Ecosystem Management, Edith Cowan University, Perth, WA, Australia.
² Centre for Integrative Metabolomics and Computational Biology, Edith Cowan University, Perth, WA, Australia.
³ Department of Primary Industries and Regional Development of Western Australia, Perth, WA, Australia.

Abstract

Captive breeding is a vital tool in the conservation of highly endangered species, as it is for the Margaret River hairy marron, Cherax tenuimanus, from the south west of Australia. A close relative, Cherax cainii, has almost completely displaced C. tenuimanus in the wild and is a successful aquaculture species, whereas C. tenuimanus has performed poorly in captivity. We used untargeted liquid chromatography-mass spectrometry to obtain metabolomic profiles of female and male C. tenuimanus held in controlled aquarium conditions during their reproductive period. Using repeated haemolymph sampling we tracked the metabolomic profiles of animals just prior to and for a period of up to 34 days after pairing with a similar sized potential mate. We identified 54 reproducible annotated metabolites including amino acids, fatty acids, biogenic amines, purine and pyrimidine metabolites and excretion metabolites. Hierarchical clustering analysis distinguished five metabolite clusters. Principal component-canonical variate analysis clearly distinguished females from males, both unpaired and paired; similar trends in profile changes in both sexes after pairing; and a striking shift in males upon pairing. We discuss three main patterns of metabolomic responses: differentiation between sexes; reactive responses to the disturbance of pairing; and convergent response to the disturbance of pairing for males. Females generally had higher concentrations of metabolites involved in metabolic rate, mobilisation of energy stores and stress. Responses to the disturbance of pairing were also related to elevated stress. Females were mobilising lipid stores to deposit yolk, whereas males had a rapid and strong response to pairing, with shifts in metabolites associated with gonad development and communication, indicating males could complete reproductive readiness only once paired with a female. The metabolomic profiles support a previously proposed potential mechanism for displacement of C. tenuimanus by C. cainii in the wild and identify several biomarkers for testing hypotheses regarding reproductive success using targeted metabolomics.

Keywords: Cherax cainii; Cherax tenuimanus; LC-MS; captive breeding; conservation; haemolymph; oxidative stress; reproduction.