Abstract
Study question
How can we select and separate X and Y-chromosome bearing sperm cells without causing cellular damage and reduced fertility?
Summary answer
AI powered SPERMAN technology can sort X and Y-chromosome bearing sperm populations without using harmful fluorescent dyes and lasers.
What is known already
Most common and reliable method to sex sorting (separation of X and Y- chromosome bearing sperm cells) is by using fluorescence activated cell sorting ( FACS) which takes advantage of the difference of amount of DNA in X and Y-chromosomes. Unfortunately this method causes reduced fertility and cellular damages due to the lasers and fluorescent dyes that are used. There are new and experimental developments in sex-sorting such as using immunological approaches to separate sperm cells. Current sorting method damages sperm cells. However, there is no automated and easy to use sperm sorting technology available.
Study design, size, duration
In this study, we have compared the quality parameters (motility, viability, AR status, DNA packaging) of sorted sperm cells to unsorted sperm cells. We have used epididymal sperm samples from 10 C57BL/6 mice (Charles River) and frozen semen samples from 6 Holstein bulls (Sexing Technologies) and frozen semen samples from 8 human sperm donors (Fairfax Cryobank). Samples were divided into two groups: sex-sorted and unsorted sperm.
Participants/materials, setting, methods
Sperm samples from 8-week-old C57BL/6 mice were collected from epididymal region, frozen bull semen samples and human semen samples were thawed at 37ºC then separated into two groups as sorted and unsorted sperm. Sorted samples in modified SP-TALP medium were loaded on the microfluidic chip of Sperman device, after the 30min long sorting process ended, all samples were centrifuged gently at 100g for 5 min, quality parameters were measured by using CASA and FACS.
Main results and the role of chance
Sperman device sorted X-bearing sperm cells at 81% purity and Y-bearing cells at 73% in mouse samples. Sperman device was able to sort X-bearing sperm cells at 78% purity and Y-bearing cells at 70% in bull samples.S perman device sorted X-bearing sperm cells at 85% purity and Y-bearing cells at 76% in human samples.
Our study shows that in mouse, bull and human sperm samples, sperm DNA quality, sperm concentration, progressive motility and AR status results from the sorting with SPERMAN device are comparable with the unsorted samples. For sperm DNA quality, both the Spearman rank correlation coefficient and concordance correlation coefficient are above 0.97, indicating a high agreement between the unsorted samples and SPERMAN sorted samples.
Limitations, reasons for caution
In this study we only compared sperm quality parameters between unsorted sperm cells and Sperman-sorted sperm cells. Ideally a follow up study would be to look in detail at fertilization success rates and embryo growth. Also, genomic and proteomic profiles of unsorted and sorted sperm cells could be different.
Wider implications of the findings: In livestock, sperm sex sorting has high value in terms of economic impact on the livestock management. Unfortunately, there is one expensive single technology dominates the sex-sorting market causing high fees poor outcomes. We believe that Sperman technology provides farmers more cheaper and better sex-sorting technology.
Trial registration number
Not applicable
Micronutrients intake is associated with improved sperm DNA quality in older men
