Scientific Methodology
Discrimination of genomic males or females is done by amplification of a unique sequence that resides in a specific gene on W chromosome that has minimal homology of this gene on Z chromosome.
Amplification of this sequence is preformed using Real Time PCR machine with specific primers designed in-house. Detection achieved using SYBR Green Supermix (Bio-Rad).
Sex reversal in birds
In chickens, sex determination takes place only after day 6 of embryonic development in which time gonads start to differentiate to ovaries or testes according to the chromosomal blueprint of the gametes. Until then, the gonads are “bi-potential”, meaning, they can differentiate into either testes or ovaries regardless of genome status29. “Soos treatment” exploits the “bi-potentiality” window of the gonads and by introducing sound vibration energy to the regular incubation profile induces up-regulation of feminine gene expression over masculine gene expression. As a result, genomic male chicks present female phenotype (ovaries) and function (laying eggs). [Okuno et. al, 2020, Scientific Reports 10:20073]
Acoustic impact on cells
Cell culture research was previously used to demonstrate the extensive effect of sound waves on cell growth, viability, differentiation, proliferation and functionality. For example, sound waves were used to promote the development of neural stem cells from the cochlear nuclei [Tao Xue et al, 2015] and viability and proliferation of human bone marrow-derived mesenchymal stem cells [Xi Chen et al, 2015]. Considering in-vitro results, raising a possible strong effect of acoustic vibrations may have on embryo and gonad development.
Immunofluorescence staining with antibodies against clusterin (CLU) in neural stem cells (NSCs) from the cochlear nuclei (protein expression of CLU). (A) Exposure to normal environment [about 40dB sound pressure level (SPL)]; (B) exposure to weakened acoustic environment (20dB SPL) for 7 days; (C) exposure to augmented acoustic environment (70dB SPL) for 7 days; (D) exposure to augmented acoustic environment (70dB SPL) for 12 days. Scale bar represents 50μm. [Tao Xue et al, 2015, Int. J. Mol. Med. 35, 637–644].
Effects of acoustic-frequency vibratory stimulation (AFVS) on cell proliferation of human bone marrow-derived mesenchymal stem cells (BM-MSCs) was improved by AFVS at 800Hz on day 7 when stimulated with AFVS at the frequencies of 0, 30, 400, and 800Hz. Values are mean ± standard error of six independent experiments (n= 6). *P < 0.05, **P < 0.01 in the indicated groups from unpaired t-test. #P < 0.05, ##P < 0.01 compared with the 0Hz control group at the same time point from unpaired t-test. [Xi Chen et al, 2015, BioMed Research International, https://doi.org/10.1155/2015/540731]
