DIET AND THE EPIGENOME Flashcards
EPIGENETICS NAME MEANING?
‘EPI’ - GREEK; OVER, ABOVE
MEANING: ‘ON TOP OF GENETICS’
MAIN EPIGEN. MECHANISMS:
DNA METHYLATION, HISTONE MODIFICATIONS, NON-CODING RNA
WHAT ARE EPIGENETIC FACTORS?
EPIGEN FACTORS CAUSING HERITABLE CHANGE IN GENE EXPRESSION WITHOUT ALTERING DNA SEQUENCE
WHAT ARE SENSITIVE WINDOWS IN EPIGENETICS?
PERIODS IN WHICH OUR EPIGENOME IS AT ITS HIGHEST VULNERABILITY TO INTRINSIC AND EXTRINSIC FACTORS
THE EPIGENOME IS INFLUENCED AND DETERMINED BY 3 TYPES OF SIGNALS:
- EXTRINSIC ENVIRONMENTAL FACTORS (DIET, EXERCISE, DRUGS)
- INTRINSIC FACTORS (EPIGEN. PROGRAMMING, REPAIR MACHINERY…); THESE ARE ALSO SUSCEPTIBLE TO CHNAGE BY EXTRINSIC FACTORS
- INHERITED EPIGEN. MARKS (BEYOND ONE’S CONTROL, INCLUDE IMPRINTED GENES AND TRANSGENERATIONAL EPIGEN.=
REPROGRAMMING OF DNA METHYLATION DURING DEVELOPMENT OCCURS IN HOW MANY WAVES?
2
IN WHICH TRIMESTER DOES THE 1ST WAVE OF DNA METHYLATION REPROGRAMMING OCCUR?
1ST
1ST WAVE LOSS OF METHYLATION IN THE GENOME INHERITED FROM WHICH PARENT HAPPENS FASTER?
THE FATHER
AT WHICH STAGE DOES THE ZYGOTE REACH THE LOWEST LEVEL OF GLOBAL AND GENOME WIDE METHYLATION?
IS THIS BEFORE AND AFTER IMPLANTATION?
BLASTULA STAGE
PRE IMPLANTATION
WHEN DOES THE METHYLATION PATTERN REMOVED FROM THE ZYGOTE START REESTABLISHING?
AFTER IMPLANTATION
WHERE DOES THE 2ND WAVE OF REPROGRAMMING OF DNA METHYLATION OCCUR?
IN THE GERM CELLS OF THE DEVELOPING EMBRYO; PRIMORDIAL GERM CELLS (PGCs)
IN WHICH WAVE OF DNA METHYLATION REPROGRAMMING ARE THE IMPRINTING GENES RESET?
ONLY IN THE 2ND WAVE
DIETARY METHYL DONORS WHICH HELP ESTABLISH FETUS’ METHYLATION PATTERN WHEN THE MOTHER CONSUMES THEM THROUGH HER DIET?
METHIONINE, FOLATE, CHOLINE, VIT B12 (COBALAMIN)
WHICH VITAMIN IS A CO FACTOR FOR METHYLATION?
B12
WHERE IN THE HUMAN BODY IS VIT B12 SYNTHESISED BUT IT CAN’T BE TAKEN UP FROM THERE SO WE NEED TO ACQUIRE IT THROUGH DIET?
BY THE BACTERIA IN THE COLON