# In vivo analysis of mammalian fertilization

> **NIH NIH R01** · BAYLOR COLLEGE OF MEDICINE · 2020 · $601,989

## Abstract

PROJECT SUMMARY/ABSTRACT
Estrous cycle, ovulation, fertilization, and pre-implantation pregnancy are fundamental reproductive processes
of clinical importance. While research has shed light on the cellular and molecular mechanisms mediating
these events, much of these data are derived from static histological analysis, low-resolution visualizations,
and studies of invertebrate models (e.g. sea urchin). Therefore, any conclusions regarding mammalian
fertilization, which takes place deep inside the body, are extrapolated and do not necessarily represent the
native state. If this technical limitation was overcome, we may gain a more complete understanding of
mammalian reproduction leading to the development of better fertility treatments and Assisted Reproductive
Technologies (ART).
By integrating expertise in live, functional optical coherence tomography (OCT) and reproductive biology, we
recently established a set of unique methods for in vivo imaging of the female mouse reproductive tract.
Our approach allows for (i) live, dynamic volumetric imaging of the mouse Fallopian tube (oviduct) with micro-
scale spatial resolution, (ii) depth-resolved mapping of oviduct cilia location and cilia beat frequency (CBF); and
(iii) tracking of individual sperm and their motility within the oviduct. None of these measurements are currently
possible with other methods, and the dynamic environment of the female reproductive tract is too complex to
model. Therefore, we are in a unique position to directly visualize specific mammalian reproductive processes
from an entirely new vantage point.
We propose the first in vivo volumetric imaging study of mammalian fertilization. This study is taking advantage
of new technological developments in OCT imaging and will allow for quantitative assessment of hormonal
regulation of oviduct cilia beating and muscle contractions, and functional analysis of fertility failures in mouse
models of human defects. This study will likely provide new insight on the process of mammalian fertilization in
its native state and lead to a better understanding of pathologies resulting in infertility. It will also establish new
functional live imaging tools, which will be a major step forward in reproductive research.
Scientific Premise, Scientific Rigor, and Relevant Biological Variables: This proposal is aimed to fill a
significant gap in the field of reproductive biology through highly innovative live imaging methods, which we
developed. All proposed experiments are supported by strong preliminary data, which have been published in
four peer-reviewed publications; one more publication is currently under review. We carefully articulated the
number of experimental animals to be used, and the rationale for the choice of the models. “Sex as a biological
variable” does not apply to our study design. Extensive details and references to our published protocols are
provided to ensure that preliminary and proposed experiments can be replicated in othe...

## Key facts

- **NIH application ID:** 9852332
- **Project number:** 5R01EB027099-02
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Irina Larina
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $601,989
- **Award type:** 5
- **Project period:** 2019-01-19 → 2022-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9852332

## Citation

> US National Institutes of Health, RePORTER application 9852332, In vivo analysis of mammalian fertilization (5R01EB027099-02). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/9852332. Licensed CC0.

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