Increase of fecundity by probiotic administration in zebrafish (Danio rerio)

Abstract

It is well known established that reproduction is sensitive to the state of energy reserves, and that there is a balance between energy homeostasis and fertility. In this view, this study examined the effects of the probiotic Lactobacillus rhamnosus, as a feed additive, on zebrafish (Danio rerio) fecundity. Ten days of probiotic treatment modulate the gene expression of neuropeptide hormones and metabolic signals, such as kiss1, kiss2 and leptin both at the CNS level and at the peripheral level. The increase in fecundity brought about by the probiotic was demonstrated by the higher number of ovulated eggs in vivo and by the higher germinal vesicle breakdown rate obtained with the in vitro maturation assay. The increase in oocyte maturation was associated with increased transcription of genes coding for signals which induce the maturation phase, such as lhcgr, cbr1l, and paqr8 genes, concomitant with a decreased transcription of genes coding for local factors which prevent oocyte maturation, such as tgfb1, gdf9, and bmp15. In conclusion, all these findings highlight the action of L. rhamnosus both on the endocrine system and at the local level by inducing oocyte maturation. The significance of the results herein obtained underlined the importance of diet in the reproductive process, supporting the hypothesis that feed additives can improve fecundity. Considering that the zebrafish has been clearly established as a vertebrate model for biomedical research, these results support the potentiality of feed additives such as probiotics, frequently used in the human diet, as a new technology to improve reproduction in all vertebrates, including humans.

Comparison of fecundity and offspring immunity in zebrafish fed Lactobacillus rhamnosus CICC 6141 and Lactobacillus casei BL23

“…3 and Table 2). The results obtained herein are consistent with those reported by Gioacchini et al (2010), wherein treatment with L. rhamnosus IMC 501 was also reported to modulate expression rates for genes coding for neuropeptide hormones and other metabolic signals (such as kiss1, kiss2, and leptin), increase the transcription rates of genes coding for signals that induce oocyte maturation (such as lhcgr, Fecundity and offspring immunity in zebrafish cbr1l, and paqr8) and decrease expression rates of genes coding for factors preventing oocyte maturation (such as tgfb1, gdf9, and bmp15). Aside from this study on strain IMC 501, there appears to have been no other studies published that document how administering probiotics affects reproductive processes in the host.…”

Beneficial Bacteria Affect Danio rerio Development by the Modulation of Maternal Factors Involved in Autophagic, Apoptotic and Dorsalizing Processes

“…Importantly, the ecological relations among gastrointestinal bacteria are responsible for benefits to the immune system [13,14,15,16,17,18,19,20], nutrient metabolism [21], growth [22], stress tolerance [23,24], vertebral column deformities, bone calcification and density [25,26,27,28], development [29,30] and reproduction [31,32,33,34], all deriving from their administration.…”

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“…Longer time between spawn resulted with lower embryo survival. In zebrafish, the growth and maturation of the oocyte occur over a period of about few days to 10 days at temperature about 27°C (Wang & Ge, 2003a, b;Csenki et al, 2010;Gioacchini et al, 2010). It might suggests that in lower temperature (19°C) in present study elongated a period of oocyte maturation.…”

“…Most fish of this species available in the market are imported from South-East Asia, where they are raised in the aquarium fish farms and in special laboratories or collected from the wild. The zebrafish has many advantages as a model organism, such as small size, reaching maturity in about three months, short reproductive cycle, easy breeding, transparent embryos and many others as possibility to spawn through the year under controlled conditions (Gioacchini et al, 2010;Dai et al, 2014). The zebrafish genome shows a high level of homology with human genome, so the importance of this species as a model species is highly increasing (Dai et al, 2014).…”

“…Many aspects, especially including spawning behavior, was mostly studied (Nasiadka & Clark, 2012;Tye et al, 2015). But some other aspects, including feeding regimes, spawning protocols depending to the prior conditions, zootechnical procedures of involved spawning which caused high number of produced and spawned eggs and high gametes quality could not be study enough (Gioacchini et al, 2010;Chen & Ge, 2013;Tye et al, 2015). Zebrafish have asynchronous ovaries, containing follicles at all stages of development (Selman et al, 1993) as well as mature eggs.…”