PMID- 9352033
OWN - NLM
STAT- MEDLINE
DCOM- 19980115
LR  - 20190914
IS  - 0148-5016 (Print)
IS  - 0148-5016 (Linking)
VI  - 39
IP  - 3
DP  - 1997 Nov-Dec
TI  - Fluorescence in situ hybridization studies on the sex chromosome constitution of 
      human sperm.
PG  - 217-22
AB  - More males are conceived than females and more males are born as a result of in 
      vitro fertilization (IVF) and donor insemination procedures. All donor sperm 
      samples are frozen for a minimum of 6 months before they are used. The ratio of 
      more boys to girls has been consistently reported over the years. A similar 
      finding has been noted in the Galway Fertility Unit at University College 
      Hospital Galway, Ireland. Traditionally, it has been accepted that the reason for 
      this excess is that a Y chromosome-bearing sperm swims faster than the X-bearing 
      sperm because it contains less DNA and is therefore "lighter." To test this 
      hypothesis, semen samples were collected at the Galway Fertility Unit from men 
      presenting for routine semen assessments. Each sample was divided into a number 
      of aliquots. The first aliquot was assessed as the "raw" ejaculate to measure the 
      initial ratio of X to Y. The second aliquot was prepared using Percoll density 
      gradients, which allows for greater recovery of sperm with higher motility and 
      improved sperm function. The final aliquot was frozen. The frozen sample was 
      later thawed and prepared using Percoll. The prepared sperm were kept for 48 h 
      and sampled at the time of preparation and at 24 h and 48 h to establish if there 
      was any differential survival over time. The X:Y ratio was analyzed using the 
      technique of fluorescence in situ hybridization (FISH). This allowed the sex 
      chromosomes to be specifically stained and identified simultaneously. No 
      difference was found in the X:Y ratio of the sperm. Therefore, any selection for 
      the Y sperm must take place at some later stage.
FAU - Dineen, T
AU  - Dineen T
AD  - Cytogenetics Unit, University College, Galway, Ireland.
FAU - Nolan, A
AU  - Nolan A
FAU - Harrington, J
AU  - Harrington J
FAU - Greer, A
AU  - Greer A
FAU - Kennedy, R
AU  - Kennedy R
FAU - Houghton, J A
AU  - Houghton JA
LA  - eng
PT  - Journal Article
PL  - England
TA  - Arch Androl
JT  - Archives of andrology
JID - 7806755
SB  - IM
MH  - Humans
MH  - *In Situ Hybridization, Fluorescence
MH  - Male
MH  - Semen Preservation
MH  - Spermatozoa/*ultrastructure
MH  - *X Chromosome
MH  - *Y Chromosome
EDAT- 1997/11/14 00:00
MHDA- 1997/11/14 00:01
CRDT- 1997/11/14 00:00
PHST- 1997/11/14 00:00 [pubmed]
PHST- 1997/11/14 00:01 [medline]
PHST- 1997/11/14 00:00 [entrez]
AID - 10.3109/01485019708987919 [doi]
PST - ppublish
SO  - Arch Androl. 1997 Nov-Dec;39(3):217-22. doi: 10.3109/01485019708987919.