Epigenetics in assisted reproductive technology

Creation, effects on embryo quality, and clinical outcomes of a new embryo culture medium with 31 optimized components derived from human oviduct fluid: A prospective multicenter randomized trial

Purpose

Our aim is to make an ideal embryo culture medium close to human oviduct fluid (HOF) components, and to evaluate the quality of this medium with embryo quality and clinical outcomes in assisted reproductive technology (ART) by a prospective randomized controlled trial (RCT).

Methods

Study I: HOF was collected laparoscopically from patients (n = 28) with normal pelvic findings. According to HOF analysis results, the new medium "HiGROW OVIT®" (OVIT) was designed. Study II: Embryos (2 pronuclei (2PN) = 9633) were assigned from 1435 patients. The blastulation rate (BR), good BR (gBR), utilized (transferred/cryo-preserved) BR (uBR), pregnancy rate (PR), and miscarriage rate (MR) were compared between the OVIT and control groups by RCT.

Results

The novel medium 'OVIT' was produced according to 31 HOF components. The concentrations of essential amino acids (e-AAs) were lower in OVIT than in current media, yet the opposite was true for ne-AA concentrations. gBR and uBR were higher in the OVIT group than in the control group. In the older female group, gBT and uBR were significantly higher in the OVIT group.

Conclusions

The novel medium 'OVIT' was produced according to HOF data. The OVIT had significantly better embryo quality and clinical outcomes than the current media.

Genetic counseling prior to assisted reproductive technology

BACKGROUND

Reproductive medicine deals with fertility and is closely related to heredity. In reproductive medicine, it is necessary to provide genetic information for the patients prior to assisted reproductive technology (ART). Japan Society for Reproductive Medicine (JSRM) requires doctors involved in reproductive medicine to have standard knowledge of reproductive genetics and knowledge of reproductive medicine, which is covered in their publication, "required knowledge of reproductive medicine."

METHODS

With the aim of providing straightforward explanations to patients in the clinical situation at pre-ART counseling, we provide the following five topics, such as (a) risk of birth defects in children born with ART, (b) chromosomal abnormalities, (c) Y chromosome microdeletions (YCMs), (d) possible chromosomal abnormal pregnancy in oligospermatozoa requiring ICSI (intracytoplasmic sperm injection), and (e) epigenetic alterations.

MAIN FINDINGS

The frequency of chromosome abnormalities in infertile patients is 0.595%-0.64%. YCMs are observed in 2%-10% of severe oligospermic men. High incidence of spermatozoa with chromosomal abnormalities has been reported in advanced oligospermia and asthenozoospermia that require ICSI. Some epigenetic alterations were reported in the children born with ART.

CONCLUSION

Certain genetic knowledge is important for professionals involved in reproductive medicine, even if they are not genetic experts.

Sperm cryopreservation in guppies and black mollies--a generalized freezing protocol for livebearers in Poeciliidae

In this study, we evaluated various parameters of sperm cryopreservation in two livebearers, guppies (Poecilia reticulata) and black mollies (P. latipinna). Our results suggested a common freezing protocol for the guppies and mollies: suspend sperm in Hanks' balanced salt solution (HBSS) at 300 mOsm/kg, use 14% glycerol as cryoprotectant, cool at 25 degrees C/min, and thaw at 40 degrees C in a water bath for 7s. Live young were produced from females inseminated with frozen-thawed sperm in both species. In guppies, percent fertilization (F) and the number of embryos (N) produced with cryopreserved sperm (F=50%, N=74, from 26 females) were similar to those of fresh controls (F=54%, N=61, from 22 females). Interestingly, this same freezing protocol has been used successfully for sperm cryopreservation in green swordtails Xiphophorus helleri, and platyfish of X. couchianus with post-thaw motility as high as 80%. All these species belong to the family of Poeciliidae, and their sperm are similar in morphology exhibiting the absence of acrosome, elongate sperm head, and the long mitochondrial sheaths. Besides their internal fertilization reproduction mode, these fish are also small in size (2-4 cm) and live in a freshwater environment. Sperm cryopreservation in fish has been generally recognized as species specific, and new protocols are required for new species. However, results presented in this study suggested otherwise. Thus, sperm cryopreservation methods optimized for one species may be applicable to others if they are taxonomical closely related species with similar sperm morphology and reproduction mode. Considering the enormous number of fish species on the planet, development of generalized sperm freezing protocols for species in groups could have additional advantages for genetic conservation.