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Consequences of lower food intake on the digestive enzymes activities, the energy reserves and the reproductive outcome in Gammarus fossarum.

Charron L, Geffard O, Chaumot A, Coulaud R, Jaffal A, Gaillet V, Dedourge-Geffard O, Geffard A - PLoS ONE (2015)

Bottom Line: Energy reserves decreased with food starvation in females, and remained stable in males.The number of embryos per female decreased with food starvation.These results underline the ecological relevance of digestive markers, as they make it possible to anticipate upcoming consequences on reproduction in females, a key biological variable for population dynamics.

View Article: PubMed Central - PubMed

Affiliation: Université Reims Champagne Ardenne, Unité Mixte de Recherche-Ineris (UMR-I02) Stress Environnementaux et Biosurveillance des milieux aquatiques, Unité de Formation et de Recherche Sciences Exactes et Naturelles, Moulin de la Housse, Reims Cedex 2, France.

ABSTRACT
Digestive enzyme activity is often used as a sensitive response to environmental pollution. However, only little is known about the negative effects of stress on digestive capacities and their consequences on energy reserves and reproduction, although these parameters are important for the maintenance of populations. To highlight if changes in biochemical responses (digestive enzymes and reserves) led to impairments at an individual level (fertility), Gammarus fossarum were submitted to a lower food intake throughout a complete female reproductive cycle (i.e. from ovogenesis to offspring production). For both males and females, amylase activity was inhibited by the diet stress, whereas trypsin activity was not influenced. These results underline similar sensitivity of males and females concerning their digestive capacity. Energy reserves decreased with food starvation in females, and remained stable in males. The number of embryos per female decreased with food starvation. Lower digestive activity in males and females therefore appears as an early response. These results underline the ecological relevance of digestive markers, as they make it possible to anticipate upcoming consequences on reproduction in females, a key biological variable for population dynamics.

No MeSH data available.


Related in: MedlinePlus

Female reproductive cycle stages (AB, C1, C2, D1 and D2, according to Geffard et al. [25]) and sampling periods for biological response measurements in males and females during the food starvation experiment.
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pone.0125154.g001: Female reproductive cycle stages (AB, C1, C2, D1 and D2, according to Geffard et al. [25]) and sampling periods for biological response measurements in males and females during the food starvation experiment.

Mentions: Female and male gammarids were sampled after 11 days during the first reproductive cycle to assess energy parameters, and after 43 days during the second reproductive cycle to assess energy and fertility parameters (Fig 1). In accordance with the reproductive cycle in the control conditions at 14±0.5°C [25], females were expected to be in the C1 (11 and 43 days) stage of their reproductive cycle. The molting stages of females were assessed throughout the experiment, and only females in AB or C1 stage were considered for biochemical analysis and fertility measurements, to avoid potential effects of a delay in the molting cycle. To accurately assess the female molt stages, the third and fourth periopod pairs (dactilopodite and protopodite) of females were cut off, mounted on a microscope slide and covered with a coverslip, and their integumental morphogenesis was observed (x 200) to discriminate among the five molt stages (AB, C1, C2, D1 and D2). Oocyte maturation and embryo development in the marsupium take place simultaneously in female gammarids in the course of the molt cycle.


Consequences of lower food intake on the digestive enzymes activities, the energy reserves and the reproductive outcome in Gammarus fossarum.

Charron L, Geffard O, Chaumot A, Coulaud R, Jaffal A, Gaillet V, Dedourge-Geffard O, Geffard A - PLoS ONE (2015)

Female reproductive cycle stages (AB, C1, C2, D1 and D2, according to Geffard et al. [25]) and sampling periods for biological response measurements in males and females during the food starvation experiment.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400123&req=5

pone.0125154.g001: Female reproductive cycle stages (AB, C1, C2, D1 and D2, according to Geffard et al. [25]) and sampling periods for biological response measurements in males and females during the food starvation experiment.
Mentions: Female and male gammarids were sampled after 11 days during the first reproductive cycle to assess energy parameters, and after 43 days during the second reproductive cycle to assess energy and fertility parameters (Fig 1). In accordance with the reproductive cycle in the control conditions at 14±0.5°C [25], females were expected to be in the C1 (11 and 43 days) stage of their reproductive cycle. The molting stages of females were assessed throughout the experiment, and only females in AB or C1 stage were considered for biochemical analysis and fertility measurements, to avoid potential effects of a delay in the molting cycle. To accurately assess the female molt stages, the third and fourth periopod pairs (dactilopodite and protopodite) of females were cut off, mounted on a microscope slide and covered with a coverslip, and their integumental morphogenesis was observed (x 200) to discriminate among the five molt stages (AB, C1, C2, D1 and D2). Oocyte maturation and embryo development in the marsupium take place simultaneously in female gammarids in the course of the molt cycle.

Bottom Line: Energy reserves decreased with food starvation in females, and remained stable in males.The number of embryos per female decreased with food starvation.These results underline the ecological relevance of digestive markers, as they make it possible to anticipate upcoming consequences on reproduction in females, a key biological variable for population dynamics.

View Article: PubMed Central - PubMed

Affiliation: Université Reims Champagne Ardenne, Unité Mixte de Recherche-Ineris (UMR-I02) Stress Environnementaux et Biosurveillance des milieux aquatiques, Unité de Formation et de Recherche Sciences Exactes et Naturelles, Moulin de la Housse, Reims Cedex 2, France.

ABSTRACT
Digestive enzyme activity is often used as a sensitive response to environmental pollution. However, only little is known about the negative effects of stress on digestive capacities and their consequences on energy reserves and reproduction, although these parameters are important for the maintenance of populations. To highlight if changes in biochemical responses (digestive enzymes and reserves) led to impairments at an individual level (fertility), Gammarus fossarum were submitted to a lower food intake throughout a complete female reproductive cycle (i.e. from ovogenesis to offspring production). For both males and females, amylase activity was inhibited by the diet stress, whereas trypsin activity was not influenced. These results underline similar sensitivity of males and females concerning their digestive capacity. Energy reserves decreased with food starvation in females, and remained stable in males. The number of embryos per female decreased with food starvation. Lower digestive activity in males and females therefore appears as an early response. These results underline the ecological relevance of digestive markers, as they make it possible to anticipate upcoming consequences on reproduction in females, a key biological variable for population dynamics.

No MeSH data available.


Related in: MedlinePlus