Morphometric and morphological analysis of the A. m. mellifera L. spermatozoa in Russia

Abstract

Honey bees are an important element of the ecological system. Today the state of the gene pool of honey bees is one of the main causes of the beekeeping crisis in the world. The quality of drone sperm is a significant factor for breeding productive bee colonies. Sperm concentration, motility, and viability of spermatozoa are an expression of sperm fertility. However, a full understanding of fertility can be obtained only by studying the morphology of spermatozoa. The purpose of this study was to describe the morphometric parameters and morphological characteristics of sperm heads of the Caucasian honey bee (A. mellifera caucasica), Bashkir honey bee (A. m. mellifera L.), of the Russian Far East honey bee (A. mellifera from far-eastern Russia) and Carnica honey bee (A. mellifera carnica) in order to determine standard features that could be used in further studies. Diff Quick staining was used to study the morphometric parameters of sperm heads. Sperm images were taken on each of the slides from a Canon 1300D digital cameras with an Altami-LUM 1 LED microscope using oil immersion at a magnification of 2000 × . Sperm images and morphometric parameters were studied using Altami Studio software version 3.5. The morphometric dimensions for area nucleus, perimeter nucleus, nucleus length and acrosome length were acquired for 200 images drone spermatozoa for each A. mellifera. Acquiring 200 images assures that a minimum of 150 properly measured sperm heads are analyses after improperly measured sperm heads are deleted from the analysis . The sperm cells were randomly selected for the morphometric analysis.  A total of 573 spermatozoa were assessed with morphometric parameters of sperm heads. The results of the morphometric analysis of drone spermatozoa show individual differences between the spermatozoa dimensions in each group. Between the A. mellifera groups the differences are not statistically significant. In this study, the min and max values of the acrosome length 3.14-5.02 µm, and nucleus length 4.02 -5.9 µm, perimeter nucleus 10.4-13.4 µm, and area nucleus 3.4-6.73 µm2, of A. mellifera spermatozoa. The morphological analysis of the drone spermatozoa revealed the presence of various abnormalities of the head (including the acrosome) and flagellum of the spermatozoa.